J. Semicond. > 2022, Volume 43 > Issue 12 > 124101

ARTICLES

Humidity sensor based on BiOBr synthesized under ambient condition

Chaofan Cao1, , Guixian Xiao1 and Yao Lu2,

+ Author Affiliations

 Corresponding author: Chaofan Cao, workchaofan@163.com; Yao Lu, yaolu@mail.tsinghua.edu.cn

DOI: 10.1088/1674-4926/43/12/124101

PDF

Turn off MathJax

Abstract: Flexible humidity sensors are effective portable devices for human respiratory monitoring. However, the current preparation of sensitive materials need harsh terms and the small production output limits their practicability. Here, we report a synthesis method of single-crystal BiOBr nanosheets under room temperature and atmospheric pressure based on a sonochemical strategy. A flexible humidity sensor enabled by BiOBr nanosheets deliver efficient sensing performance, a high humidity sensitivity (Ig/I0 = 550%) with relative humidity from 40% to 100%, an excellent selectivity, and a detection response/recovery time of 11 and 6 s, respectively. The flexible humidity sensor shows a potential application value as a wearable monitoring device for respiratory disease prevention and health monitoring.

Key words: human breathing, BiOBr nanosheets, sonochemical strategy, flexible humidity sensor

Breathing is a rhythmic activity of the human body, and its frequency and strength depend on the level of the body’s activity. The main purpose of breathing is to provide oxygen to the body and remove carbon dioxide[1, 2]. The humidity, concentration, flow rate, and pressure of breathing are important indicators for disease diagnosis, treatment and prognosis evaluation, as well as pulmonary function projects in medicine and other fields[3-5]. Wearable devices such as wearable humidity sensors, can easily conform to and integrate with human skin, machines, and other curved surfaces, which enable rapid, continuous, and noninvasive capture of the breathing state[6-10].

At present, the research on flexible humidity sensors mainly focuses on resistive and capacitive types[11-15]. Among them, the resistive humidity sensors have widely been studied due to their simple fabrication and easy integration. The resistive humidity sensors display a resistance-change signal when the sensing material interacts with water molecules[13, 16]. Various moisture-sensitive materials have been explored to date, such as graphene oxide (GO)[17], carbon nanotubes[18], two-dimensional materials[19], and porous membranes[16]. For example, Xu et al.[20] reported a humidity sensor based on supramolecular graphene modified with sodium naphthalene-1-sulfonate and silver nanoparticles. Their sensor has a high sensitivity to humidity and a fast response and recovery time (≤1 s). However, GO prepared by Hummer's method requires strong acid-corrosion resistance and a complex modification process, which greatly increases the cost and power consumption of the sensor. A recent humidity sensor based on a two-dimensional MoS2 field-effect transistor requires a high gate operating voltage (80 V) and a complex preparation process; therefore, this sensor also increases the power consumption and incurs a high manufacturing cost[21]. Although these materials have interesting structural and electronic properties, high sensitivity, and fast response time, their production costs remain excessively high and the fabrication processes are complex. Therefore, high-performance humidity sensors fabricated from cheap materials through simple processes are in great demand.

BiOBr is one of the important bismuth oxide halide compounds. It is a ternary V–VI–VII semiconductor compound with tetragonal crystal structure. The layered structure of BiOBr is composed of tetragonal [Bi2O2]2+ plates sandwiched between two Br ion plates. This inherent layered structure gives these materials fascinating optical, mechanical and electrical properties. At the same time, BiOBr can be prepared by various methods, such as hydrothermal[22], liquid-phase exfoliation[23], self-sacrifice template[24], which is considered to be an efficient material in a wide range of application. Here, we report a single-crystal BiOBr nanostructures synthesized using sonochemical methods under mild conditions. This method is simple and the reaction is completed at room temperature. Additionally, the synthesized BiOBr nanosheets have excellent humidity-sensing performance and ultrahigh selectivity. The fabricated humidity sensor based on BiOBr delivered a high humidity sensitivity (Ig/I0 = 550%) from 40% to 100% RH and response/recovery time: 11 and 6 s, respectively, and showed an excellent humidity selectivity of BiOBr. The sensor can also detect the respiratory rate and gas volume of the human body. The prepared face masks have a large-scale application in the diagnosis of pulmonary function.

2.1 Materials

The raw materials of the pure metals bismuth (Bi, 99.99%, ≥150 mesh) powder and hydrogen peroxide (H2O2, 30%) are commercially available and were obtained from Sigma-Aldrich. The hydrobromic acid (HBr) was purchased from Sinopharm Chemical Reagent Co., Ltd. Home-made deionized water (DI H2O) was used for all experiments.

2.2 Synthesis of BiOBr nanostructures

Fig. 1 shows the preparation of BiOBr nanostructures from the source material (Bi powder) via the sonochemical strategy under environmental conditions. In a typical experiment, 1 mmol Bi powder was added into the mixture solution with 5 mL H2O2 and 10 mL H2O to form the suspension solution by stirring at a speed of 400 r/min. Then, 1 mL 1 M HBr was added into the suspension solution, and followed ultrasonic treatment at a frequency of 40 kHz for 2 h. The resultant products were collected by centrifugation and washed with H2O for three times. Finally, the precipitate was dried under ambient conditions.

Fig. 1.  (Color online) Schematic illustration on growing BiOBr nanostructures under ultrasonic treatment.
DownLoad: Full-Size Img PowerPoint

2.3 Preparation of the humidity sensor

A 60 nm Au interdigital pattern was first deposited on the PET substrate by photolithography and thermal evaporation, and a flexible interdigital electrode was prepared, as shown in Figs. 2(a)–2(e). The prepared BiOBr was then dispersed in ethanol solution by ultrasound, and the prepared BiOBr ethanol solution was spin coated on the electrode at 300 r/min. Finally, the equipment was baked on a hot plate at 80 °C for 10 min to add BiOBr materials and electrodes.

Fig. 2.  (Color online) (a) Spin coating photoresist on PET substrate. (b) UV exposure under interdigital electrode patterned mask. (c) Develop the exposed PET substrate. (d) Thermal evaporation 60 nm Au electrode. (e) Acetone stripping to form interpolation gold electrode.
DownLoad: Full-Size Img PowerPoint

2.4 Microstructural characterizations

Powder X-ray diffraction (XRD, D8 Advance, Bruker, Germany) was utilized to evaluate the phase compositions under Cu Kα X-ray radiation (λ = 1.5406 Å). The microstructure and morphology of as-prepared samples were observed under a field emission scanning electron microscope (FESEM, S-4800, Hitachi, Japan) and high-resolution transmission electron microscopy (HRTEM, JEM-2100F, JEOL, Japan) equipped with energy dispersive X-ray spectroscopy (EDX, Quantax-STEM, Bruker, Germany). The compositions and valence band of the product were analyzed by X-ray photoelectron spectroscopy (XPS, Scientific K-Alpha, Thermo, USA), with a reference of C 1s peak at 284.6 eV. The photoluminescence was tested on a spectrometer (Fluromax-4P, Horiba Jobin Yvon, France) that was excited at 350 nm.

3.1 BiOBr nanostructures

The successful preparation of BiOBr was characterized through SEM, X-ray diffraction, TEM, IR, and XPS. Panels a and b of Fig. 3 displays SEM images of the Bi powder and BiOBr nanostructures, respectively. As shown in the images, the sonochemical strategy successfully incorporated the Bi powder into BiOBr nanosheets. After a statistical analysis of the particles in the SEM images, the approximate size range of the synthesized BiOBr nanostructures was determined as 0.5–1.5 μm (see Fig. 3(b), an enlarged view of Fig. 3(c)). The X-ray diffraction pattern of BiOBr (Fig. 3(d)) is consistent with JCPDS card No. 09-0393. The Raman spectrum of the BiOBr nanosheets is shown in Fig. 3(e). The spectral peaks at 57.4, 90.6, 112.1, and 160.5 cm–1 excited by 532 nm light were assigned to BiOBr. Furthermore, square nanostructures were observed in the TEM images. The HRTEM images (Fig. 3(f)) displayed clear lattice fringes with an interplanar spacing of 0.28 nm, corresponding to the (110) plane of BiOBr.

Fig. 3.  (Color online) (a) SEM image of Bi powder. (b, c) SEM images of BiOBr nanostructure under different magnifications. (d) Typical XRD pattern of BiOBr nanostructure. (e) Raman spectrum of BiOBr nanostructure excited at 532 nm. (f) HRTEM images of BiOBr nanostructure，the down-left insets are the lattice fringes.
DownLoad: Full-Size Img PowerPoint

The elemental valence states and chemical compositions on the surfaces of the BiOBr nanosheets were analyzed using XPS. The measured XPS spectra (Fig. 4(a)) confirm the presence of only Bi, O, and Br elements in both samples. The peaks located at 159.1 and 164.4 eV in the Bi 3b spectrum of the BiOBr nanosheets (Fig. 4(b)) correspond to Bi 4f 5/2 and Bi 4f 7/2, respectively. Furthermore, the spin-orbit splitting energy between these two peaks is 5.3 eV, which indicates that normal Bi3+ resided on the nanosheet surfaces. However, the overall spectral distribution of the nanosheets shifted toward higher binding energies than those of pure Bi, indicating a high oxidation state of Bi in the nanosheets. According to previous studies, new peaks appear when the binding energies of 160.1 and 165.4 eV are raised by the higher valence of Bi5+. The peaks at 69.2 and 70.6 eV in Fig. 4(c) correspond to Br 3d5/2 and Br 3d3/2, respectively. The O1s spectrum of the BiOBr sample (Fig. 4(d)) is broad and asymmetric and could be fitted to two peaks. The peaks appearing at high and low binding energies were assigned to surface-adsorbed oxygen and lattice oxygen components in the sample, respectively.

Fig. 4.  (Color online) (a) XPS survey scan of BiOBr nanostructure. (b–d) High-resolution XPS spectra of Bi 4f, Br 3d and O 1s of BiOBr, respectively.
DownLoad: Full-Size Img PowerPoint

3.2 Humidity sensing properties

A BiOBr-based flexible humidity sensor was fabricated and its performance was characterized at 40% RH and 25 °C (Fig. 5(a)). Fig. 5(b) plots the sensitivities of the BiOBr humidity sensor as functions of time at different RH (0%–100%). The relative current of the sensor decreased over the humidity range 0%–30% and increased over the humidity range 50%–100% because our test was performed in an air environment with 40% RH. The humidity-dependent relative current variations of the sensor are clarified in Fig. 5(c). As the humidity increased from 0% to 100% RH, the relative current of the sensor increased to 1200%. This indicates that our sensor is highly sensitive to humidity.

Fig. 5.  (Color online) (a) Schematic illustration of a humidity sensor based on BiOBr nanostructure. (b) Time-dependent variation of relative current change of device under various concentrations of relative humidity. (c) Relative current change of sensor under different humidity relative to 0% humidity. (d) Response and recovery of the humidity sensor exposed to 90%. (e) Relative current changes of the humidity sensor under cyclic run between ambient humidity and 90% RH. (f) For the influence of other gases on the performance of humidity sensor, the relative humidity of the test environment is 40% RH, and the gas concentration is 100 ppm.
DownLoad: Full-Size Img PowerPoint

In addition, the response and recovery time are important parameters of a humidity sensor in practical applications such as respiratory monitoring. In this work, we measured the time required for the sensor to reach equilibrium (95% of the maximum change) between 40% and 90% RH. During the measurement, the resistance change was measured while alternately moving the sensor between two humidity environments. The response and recovery time of the sensor were 10 and 6 s, respectively (Fig. 5(d)). We also characterized the cyclic stability of the device (Fig. 5(e)). When the humidity changed repeatedly between 40% and 90% RH, the response signal of the sensor fluctuated only slightly, indicating strong cycle performance and stability. Moreover, during respiration detection, the humidity sensor is directly interfered with by gas, so high selectivity for humidity is essential. The electrical response of the humidity sensor in the atmosphere of ethanol, acetone and ammonia gas. During the test, the relative humidity of the environment is controlled to be 40% and the gas concentration is 100 ppm. The test results are shown in Fig. 5(f). It can be seen that when the humidity sensor works at room temperature, its relative current basically does not change in the presence of ethanol, acetone, and ammonia. This indicates that the humidity sensor can be used as a highly selective humidity sensor.

3.3 Breathing monitoring

Given the excellent humidity performance and fast response time of the humidity sensor, we incorporated the sensor into an intelligent mask that detects human respiration in real time. As shown in Figs. 6(a) and 6(b), our smart mask is composed of sensors installed in a breathing valve. When the mask is worn, the user’s breathing is detected in a relatively closed space. As the current of the sensor increases or decreases with each breath, we can monitor the changing intensity and frequency of the respiration by monitoring the magnitude and number of peaks, respectively. Fig. 6(c) compares the relative current changes of the sensor during deep and normal breathing. The intensity was much higher during deep breathing than during normal breathing. This implies that the sensor can detect the vital capacity. Additionally, the current of the smart mask increased and decreased in synchrony with the breathing pattern, so the changes in respiratory rate can be monitored through the number of peaks. As shown in Figs. 6(d)–6(f), our smart mask can monitor breathing at different frequencies (slow, normal, and fast) in real time. These results show that our intelligent mask can measure the respiratory status of the human body and help medical diagnoses of lung disease.

Fig. 6.  (Color online) (a) The application of a humidity sensor in human respiratory monitoring is intelligent mask. (b) Photos of humidity sensors. (c) Response of the sensor under various breathing modes. (d–f) The smart mask's response under different breathing rates.
DownLoad: Full-Size Img PowerPoint

We have developed a high-performance flexible humidity sensor that is based on a sensitive material composed of BiOBr single-crystal biological nanostructured nanosheets. The material is prepared using a simple, low-cost sonochemical method suitable for large-scale production and demonstrates excellent humidity properties, with a humidity sensitivity of 550% (Ig/I0) from 40% to 100% RH, response and recovery time 11 and 6 s, respectively, and excellent selectivity for humidity. In experimental demonstrations, the sensor successfully detected human respiration patterns. This cost-effective flexible humidity sensor has potential applications in the diagnosis and treatment of respiratory diseases; for instance, as a wearable respiratory monitoring device for infection reduction and health monitoring.

Acknowledgements: The authors sincerely acknowledge financial support from the China Postdoctoral Science Foundation (No. 2021M691729), National Key R&D Program of China (No. 2021YFB2401901), Tsinghua-Toyota Joint Research Fund (No. 20213930025).


[1]
Rolfe S. The importance of respiratory rate monitoring. Brit J Nurs, 2019, 28(8), 504 doi: 10.12968/bjon.2019.28.8.504
[2]
Jonkman A H, De Vries H J, Heunks L M A. Physiology of the respiratory drive in ICU patients: implications for diagnosis and treatment. Crit Care, 2020, 24(1), 1 doi: 10.1186/s13054-019-2683-3
[3]
Bigatello L, Pesenti A. Respiratory physiology for the anesthesiologist. Anesthesiology, 2019, 130(6), 1064 doi: 10.1097/ALN.0000000000002666
[4]
McCafferty J. Respiratory heat and moisture loss in health, asthma and chronic obstructive pulmonary disease (COPD). University of Edinburgh, 2006
[5]
Sylvester K P, Youngs L, Rutter M A, et al. Early respiratory diagnosis: benefits of enhanced lung function assessment. BMJ Open Respir Res, 2021, 8(1), e001012 doi: 10.1136/bmjresp-2021-001012
[6]
Baldo T A, de Lima L F, Mendes L F, et al. Wearable and biodegradable sensors for clinical and environmental applications. ACS Appl Electron Mater, 2020, 3(1), 68 doi: 10.1021/acsaelm.0c00735
[7]
Lu Y, Xu K, Zhang L, et al. Multimodal plant healthcare flexible sensor system. ACS Nano, 2020, 14(9), 10966 doi: 10.1021/acsnano.0c03757
[8]
Li B, Xiao G, Liu F, et al. A flexible humidity sensor based on silk fabrics for human respiration monitoring. J Mater Chem C, 2018, 6(16), 4549 doi: 10.1039/C8TC00238J
[9]
Peng B, Zhao F, Ping J, et al. Recent Advances in nanomaterial‐enabled wearable sensors: Material synthesis, sensor design, and personal health monitoring. Small, 2020, 16(44), 2002681 doi: 10.1002/smll.202002681
[10]
Leng X, Wang Y, Wang F. Alcohols assisted hydrothermal synthesis of defect-rich MoS2 and their applications in humidity sensing. Adv Mater Interfaces, 2019, 6(11), 1900010 doi: 10.1002/admi.201900010
[11]
Al-Sehemi A G, Al-Assiri M S, Kalam A, et al. Sensing performance optimization by tuning surface morphology of organic (D-π-A) dye based humidity sensor. Sens Actuators B, 2016, 231, 30 doi: 10.1016/j.snb.2016.03.004
[12]
Lu Y, Xu K, Yang M Q, et al. Highly stable Pd/HNb3O8-based flexible humidity sensor for perdurable wireless wearable applications. Nanoscale Horiz, 2021, 6(3), 260 doi: 10.1039/D0NH00594K
[13]
Wang Y F, Sekine T, Takeda Y, et al. Fully printed PEDOT: PSS-based temperature sensor with high humidity stability for wireless healthcare monitoring. Sci Rep, 2020, 10(1), 1 doi: 10.1038/s41598-019-56847-4
[14]
Bae Y M, Lee Y H, Kim H S, et al. Polyimide-polyurethane/urea block copolymers for highly sensitive humidity sensor with low hysteresis. J Appl Polym Sci, 2017, 134(24), 44973 doi: 10.1002/app.44973
[15]
Farahani H, Wagiran R, Hamidon M N. Humidity sensors principle, mechanism, and fabrication technologies: a comprehensive review. Sensors, 2014, 14(5), 7881 doi: 10.3390/s140507881
[16]
An H, Habib T, Shah S, et al. Water sorption in MXene/polyelectrolyte multilayers for ultrafast humidity sensing. ACS Appl Nano Mater, 2019, 2(2), 948 doi: 10.1021/acsanm.8b02265
[17]
Leng X, Luo D, Xu Z, et al. Modified graphene oxide/Nafion composite humidity sensor and its linear response to the relative humidity. Sens Actuators B, 2018, 257, 372 doi: 10.1016/j.snb.2017.10.174
[18]
Zhu P, Liu Y, Fang Z, et al. Flexible and highly sensitive humidity sensor based on cellulose nanofibers and carbon nanotube composite film. Langmuir, 2019, 35(14), 4834 doi: 10.1021/acs.langmuir.8b04259
[19]
Yang J, Shi R, Lou Z, et al. Flexible smart noncontact control systems with ultrasensitive humidity sensors. Small, 2019, 15(38), 1902801 doi: 10.1002/smll.201902801
[20]
Wang S, Chen Z, Umar A, et al. Supramolecularly modified graphene for ultrafast responsive and highly stable humidity sensor. J Phys Chem C, 2015, 119(51), 28640 doi: 10.1021/acs.jpcc.5b08771
[21]
Zhao J, Li N, Yu H, et al. Highly sensitive MoS2 humidity sensors array for noncontact sensation. Adv Mater, 2017, 29(34), 1702076 doi: 10.1002/adma.201702076
[22]
Vadivel S, Vanitha M, Muthukrishnaraj A, et al. Graphene oxide–BiOBr composite material as highly efficient photocatalyst for degradation of methylene blue and rhodamine-B dyes. J Water Proc Eng, 2014, 1, 17 doi: 10.1016/j.jwpe.2014.02.003
[23]
Yu H, Huang H, Xu K, et al. Liquid-phase exfoliation into monolayered BiOBr nanosheets for photocatalytic oxidation and reduction. ACS Sustaine Chem Eng, 2017, 5(11), 10499 doi: 10.1021/acssuschemeng.7b02508
[24]
Peng Y, Xu J, Liu T, et al. Controlled synthesis of one-dimensional BiOBr with exposed (110) facets and enhanced photocatalytic activity. CrystEngComm, 2017, 19(43), 6473 doi: 10.1039/C7CE01452J
Fig. 1.  (Color online) Schematic illustration on growing BiOBr nanostructures under ultrasonic treatment.

DownLoad: Full-Size Img PowerPoint
Fig. 2.  (Color online) (a) Spin coating photoresist on PET substrate. (b) UV exposure under interdigital electrode patterned mask. (c) Develop the exposed PET substrate. (d) Thermal evaporation 60 nm Au electrode. (e) Acetone stripping to form interpolation gold electrode.

DownLoad: Full-Size Img PowerPoint
Fig. 3.  (Color online) (a) SEM image of Bi powder. (b, c) SEM images of BiOBr nanostructure under different magnifications. (d) Typical XRD pattern of BiOBr nanostructure. (e) Raman spectrum of BiOBr nanostructure excited at 532 nm. (f) HRTEM images of BiOBr nanostructure，the down-left insets are the lattice fringes.

DownLoad: Full-Size Img PowerPoint
Fig. 4.  (Color online) (a) XPS survey scan of BiOBr nanostructure. (b–d) High-resolution XPS spectra of Bi 4f, Br 3d and O 1s of BiOBr, respectively.

DownLoad: Full-Size Img PowerPoint
Fig. 5.  (Color online) (a) Schematic illustration of a humidity sensor based on BiOBr nanostructure. (b) Time-dependent variation of relative current change of device under various concentrations of relative humidity. (c) Relative current change of sensor under different humidity relative to 0% humidity. (d) Response and recovery of the humidity sensor exposed to 90%. (e) Relative current changes of the humidity sensor under cyclic run between ambient humidity and 90% RH. (f) For the influence of other gases on the performance of humidity sensor, the relative humidity of the test environment is 40% RH, and the gas concentration is 100 ppm.

DownLoad: Full-Size Img PowerPoint
Fig. 6.  (Color online) (a) The application of a humidity sensor in human respiratory monitoring is intelligent mask. (b) Photos of humidity sensors. (c) Response of the sensor under various breathing modes. (d–f) The smart mask's response under different breathing rates.

DownLoad: Full-Size Img PowerPoint
[1]
Rolfe S. The importance of respiratory rate monitoring. Brit J Nurs, 2019, 28(8), 504 doi: 10.12968/bjon.2019.28.8.504
[2]
Jonkman A H, De Vries H J, Heunks L M A. Physiology of the respiratory drive in ICU patients: implications for diagnosis and treatment. Crit Care, 2020, 24(1), 1 doi: 10.1186/s13054-019-2683-3
[3]
Bigatello L, Pesenti A. Respiratory physiology for the anesthesiologist. Anesthesiology, 2019, 130(6), 1064 doi: 10.1097/ALN.0000000000002666
[4]
McCafferty J. Respiratory heat and moisture loss in health, asthma and chronic obstructive pulmonary disease (COPD). University of Edinburgh, 2006
[5]
Sylvester K P, Youngs L, Rutter M A, et al. Early respiratory diagnosis: benefits of enhanced lung function assessment. BMJ Open Respir Res, 2021, 8(1), e001012 doi: 10.1136/bmjresp-2021-001012
[6]
Baldo T A, de Lima L F, Mendes L F, et al. Wearable and biodegradable sensors for clinical and environmental applications. ACS Appl Electron Mater, 2020, 3(1), 68 doi: 10.1021/acsaelm.0c00735
[7]
Lu Y, Xu K, Zhang L, et al. Multimodal plant healthcare flexible sensor system. ACS Nano, 2020, 14(9), 10966 doi: 10.1021/acsnano.0c03757
[8]
Li B, Xiao G, Liu F, et al. A flexible humidity sensor based on silk fabrics for human respiration monitoring. J Mater Chem C, 2018, 6(16), 4549 doi: 10.1039/C8TC00238J
[9]
Peng B, Zhao F, Ping J, et al. Recent Advances in nanomaterial‐enabled wearable sensors: Material synthesis, sensor design, and personal health monitoring. Small, 2020, 16(44), 2002681 doi: 10.1002/smll.202002681
[10]
Leng X, Wang Y, Wang F. Alcohols assisted hydrothermal synthesis of defect-rich MoS2 and their applications in humidity sensing. Adv Mater Interfaces, 2019, 6(11), 1900010 doi: 10.1002/admi.201900010
[11]
Al-Sehemi A G, Al-Assiri M S, Kalam A, et al. Sensing performance optimization by tuning surface morphology of organic (D-π-A) dye based humidity sensor. Sens Actuators B, 2016, 231, 30 doi: 10.1016/j.snb.2016.03.004
[12]
Lu Y, Xu K, Yang M Q, et al. Highly stable Pd/HNb3O8-based flexible humidity sensor for perdurable wireless wearable applications. Nanoscale Horiz, 2021, 6(3), 260 doi: 10.1039/D0NH00594K
[13]
Wang Y F, Sekine T, Takeda Y, et al. Fully printed PEDOT: PSS-based temperature sensor with high humidity stability for wireless healthcare monitoring. Sci Rep, 2020, 10(1), 1 doi: 10.1038/s41598-019-56847-4
[14]
Bae Y M, Lee Y H, Kim H S, et al. Polyimide-polyurethane/urea block copolymers for highly sensitive humidity sensor with low hysteresis. J Appl Polym Sci, 2017, 134(24), 44973 doi: 10.1002/app.44973
[15]
Farahani H, Wagiran R, Hamidon M N. Humidity sensors principle, mechanism, and fabrication technologies: a comprehensive review. Sensors, 2014, 14(5), 7881 doi: 10.3390/s140507881
[16]
An H, Habib T, Shah S, et al. Water sorption in MXene/polyelectrolyte multilayers for ultrafast humidity sensing. ACS Appl Nano Mater, 2019, 2(2), 948 doi: 10.1021/acsanm.8b02265
[17]
Leng X, Luo D, Xu Z, et al. Modified graphene oxide/Nafion composite humidity sensor and its linear response to the relative humidity. Sens Actuators B, 2018, 257, 372 doi: 10.1016/j.snb.2017.10.174
[18]
Zhu P, Liu Y, Fang Z, et al. Flexible and highly sensitive humidity sensor based on cellulose nanofibers and carbon nanotube composite film. Langmuir, 2019, 35(14), 4834 doi: 10.1021/acs.langmuir.8b04259
[19]
Yang J, Shi R, Lou Z, et al. Flexible smart noncontact control systems with ultrasensitive humidity sensors. Small, 2019, 15(38), 1902801 doi: 10.1002/smll.201902801
[20]
Wang S, Chen Z, Umar A, et al. Supramolecularly modified graphene for ultrafast responsive and highly stable humidity sensor. J Phys Chem C, 2015, 119(51), 28640 doi: 10.1021/acs.jpcc.5b08771
[21]
Zhao J, Li N, Yu H, et al. Highly sensitive MoS2 humidity sensors array for noncontact sensation. Adv Mater, 2017, 29(34), 1702076 doi: 10.1002/adma.201702076
[22]
Vadivel S, Vanitha M, Muthukrishnaraj A, et al. Graphene oxide–BiOBr composite material as highly efficient photocatalyst for degradation of methylene blue and rhodamine-B dyes. J Water Proc Eng, 2014, 1, 17 doi: 10.1016/j.jwpe.2014.02.003
[23]
Yu H, Huang H, Xu K, et al. Liquid-phase exfoliation into monolayered BiOBr nanosheets for photocatalytic oxidation and reduction. ACS Sustaine Chem Eng, 2017, 5(11), 10499 doi: 10.1021/acssuschemeng.7b02508
[24]
Peng Y, Xu J, Liu T, et al. Controlled synthesis of one-dimensional BiOBr with exposed (110) facets and enhanced photocatalytic activity. CrystEngComm, 2017, 19(43), 6473 doi: 10.1039/C7CE01452J
1

Interfacial engineering of printable bottom back metal electrodes for full-solution processed flexible organic solar cells

Hongyu Zhen, Kan Li, Yaokang Zhang, Lina Chen, Liyong Niu, et al.

Journal of Semiconductors, 2018, 39(1): 014002. doi: 10.1088/1674-4926/39/1/014002
2

Hybrid functional microfibers for textile electronics and biosensors

Bichitra Nanda Sahoo, Byungwoo Choi, Jungmok Seo, Taeyoon Lee

Journal of Semiconductors, 2018, 39(1): 011009. doi: 10.1088/1674-4926/39/1/011009
3

Stretchable human-machine interface based on skin-conformal sEMG electrodes with self-similar geometry

Wentao Dong, Chen Zhu, Wei Hu, Lin Xiao, Yong’an Huang, et al.

Journal of Semiconductors, 2018, 39(1): 014001. doi: 10.1088/1674-4926/39/1/014001
4

Review of recent progresses on flexible oxide semiconductor thin film transistors based on atomic layer deposition processes

Jiazhen Sheng, Ki-Lim Han, TaeHyun Hong, Wan-Ho Choi, Jin-Seong Park, et al.

Journal of Semiconductors, 2018, 39(1): 011008. doi: 10.1088/1674-4926/39/1/011008
5

Inkjet printed large-area flexible circuits: a simple methodology for optimizing the printing quality

Tao Cheng, Youwei Wu, Xiaoqin Shen, Wenyong Lai, Wei Huang, et al.

Journal of Semiconductors, 2018, 39(1): 015001. doi: 10.1088/1674-4926/39/1/015001
6

Flexible devices: from materials, architectures to applications

Mingzhi Zou, Yue Ma, Xin Yuan, Yi Hu, Jie Liu, et al.

Journal of Semiconductors, 2018, 39(1): 011010. doi: 10.1088/1674-4926/39/1/011010
7

Ultrathin free-standing graphene oxide film based flexible touchless sensor

Lin Liu, Yingyi Wang, Guanghui Li, Sujie Qin, Ting Zhang, et al.

Journal of Semiconductors, 2018, 39(1): 013002. doi: 10.1088/1674-4926/39/1/013002
8

Printable inorganic nanomaterials for flexible transparent electrodes: from synthesis to application

Dingrun Wang, Yongfeng Mei, Gaoshan Huang

Journal of Semiconductors, 2018, 39(1): 011002. doi: 10.1088/1674-4926/39/1/011002
9

Silver nanowire/polymer composite soft conductive film fabricated by large-area compatible coating for flexible pressure sensor array

Sujie Chen, Siying Li, Sai Peng, Yukun Huang, Jiaqing Zhao, et al.

Journal of Semiconductors, 2018, 39(1): 013001. doi: 10.1088/1674-4926/39/1/013001
10

Steady-state solution growth of microcrystalline silicon on nanocrystalline seed layers on glass

R. Bansen, C. Ehlers, Th. Teubner, T. Boeck

Journal of Semiconductors, 2016, 37(9): 093001. doi: 10.1088/1674-4926/37/9/093001
11

Progress in complementary metal-oxide-semiconductor silicon photonics and optoelectronic integrated circuits

Hongda Chen, Zan Zhang, Beiju Huang, Luhong Mao, Zanyun Zhang, et al.

Journal of Semiconductors, 2015, 36(12): 121001. doi: 10.1088/1674-4926/36/12/121001
12

Synthesis of metal oxide composite nanosheets and their pressure sensing properties

Muhammad Tariq Saeed Chani, Sher Bahadar Khan, Kh. S. Karimov, M. Abid, Abdullah M. Asiri, et al.

Journal of Semiconductors, 2015, 36(2): 023002. doi: 10.1088/1674-4926/36/2/023002
13

Resistive humidity sensor based on vanadium complex films

Kh. S. Karimov, M. Saleem, M. Mahroof-Tahir, R. Akram, M.T. Saeed Chanee, et al.

Journal of Semiconductors, 2014, 35(9): 094001. doi: 10.1088/1674-4926/35/9/094001
14

Humidity sensing properties of Cu2O-PEPC nanocomposite films

Kh. S. Karimov, M. Saleem, Z. M. Karieva, A. Mateen, M. Tariq Saeed Chani, et al.

Journal of Semiconductors, 2012, 33(7): 073001. doi: 10.1088/1674-4926/33/7/073001
15

Surface-type humidity sensor based on cellulose-PEPC for telemetry systems

Kh. S. Karimov, M. Saleem, T. A. Qasuria, M. Farooq

Journal of Semiconductors, 2011, 32(1): 015005. doi: 10.1088/1674-4926/32/1/015005
16

Optical and electrical properties of electrochemically deposited polyaniline-CeO2 hybrid nanocomposite film

Anees A. Ansari, M. A. M. Khan, M. Naziruddin Khan, Salman A. Alrokayan, M. Alhoshan, et al.

Journal of Semiconductors, 2011, 32(4): 043001. doi: 10.1088/1674-4926/32/4/043001
17

Formation of stacked ruthenium nanocrystals embedded in SiO2 for nonvolatile memory applications

Mao Ping, Zhang Zhigang, Pan Liyang, Xu Jun, Chen Peiyi, et al.

Journal of Semiconductors, 2009, 30(9): 093003. doi: 10.1088/1674-4926/30/9/093003
18

A New CMOS Image Sensor with a High Fill Factor and the Dynamic Digital Double Sampling Technique

Liu Yu, Wang Guoyu

Chinese Journal of Semiconductors , 2006, 27(2): 313-317.

19

An Air-Breathing Micro Direct Methanol Fuel Cell with 3D KOH-Etched Cathode Structure

Jiang Yingqi, Wang Xiaohong, Zhong Lingyan, Liu Litian

Chinese Journal of Semiconductors , 2006, 27(3): 478-481.

20

Electronic Structure of Semiconductor Nanocrystals

Li Jingbo, Wang Linwang, Wei Suhuai

Chinese Journal of Semiconductors , 2006, 27(2): 191-196.

1. Das, T.K., Jesionek, M., Mistewicz, K. et al. BiOI: Self-Powered Humidity Sensor and Breath Monitor. Advanced Materials Technologies, 2025. doi:10.1002/admt.202401988
2. Sereika, R., Varnagiris, Š., Urbonavičius, M. et al. Synthesis and properties of quasi-one-dimensional BiSBr crystals via the Bridgman-Stockbarger technique. Journal of Crystal Growth, 2024. doi:10.1016/j.jcrysgro.2024.127816

    • Search

    Advanced Search >>

    GET CITATION

    Chaofan Cao, Guixian Xiao, Yao Lu. Humidity sensor based on BiOBr synthesized under ambient condition[J]. Journal of Semiconductors, 2022, 43(12): 124101. doi: 10.1088/1674-4926/43/12/124101
    C F Cao, G X Xiao, Y Lu. Humidity sensor based on BiOBr synthesized under ambient condition[J]. J. Semicond, 2022, 43(12): 124101. doi: 10.1088/1674-4926/43/12/124101
    shu

    Export: BibTex EndNote

    Article Metrics

    Article views: 941 Times PDF downloads: 52 Times Cited by: 2 Times

    History

    Received: 30 June 2022 Revised: 25 July 2022 Online: Accepted Manuscript: 08 September 2022Uncorrected proof: 08 September 2022Published: 02 December 2022

    Catalog

      Email This Article

      User name:
      Email:*请输入正确邮箱
      Code:*验证码错误
      Send
      Article Navigation >  Journal of Semiconductors  > 2022  >  43(12): 124101
      Chaofan Cao, Guixian Xiao, Yao Lu. Humidity sensor based on BiOBr synthesized under ambient condition[J]. Journal of Semiconductors, 2022, 43(12): 124101. doi: 10.1088/1674-4926/43/12/124101 ****C F Cao, G X Xiao, Y Lu. Humidity sensor based on BiOBr synthesized under ambient condition[J]. J. Semicond, 2022, 43(12): 124101. doi: 10.1088/1674-4926/43/12/124101
      Citation:
      Chaofan Cao, Guixian Xiao, Yao Lu. Humidity sensor based on BiOBr synthesized under ambient condition[J]. Journal of Semiconductors, 2022, 43(12): 124101. doi: 10.1088/1674-4926/43/12/124101 ****
      C F Cao, G X Xiao, Y Lu. Humidity sensor based on BiOBr synthesized under ambient condition[J]. J. Semicond, 2022, 43(12): 124101. doi: 10.1088/1674-4926/43/12/124101
      shu

      Humidity sensor based on BiOBr synthesized under ambient condition

      DOI: 10.1088/1674-4926/43/12/124101
      • 1.

        Second Affiliated Hospital, Shenyang Medical College, Shenyang 110035, China

      • 2.

        State Key Laboratory of Automotive Safety and Energy, School of Vehicle and Mobility, Tsinghua University, Beijing 100084, China

      More Information
      • Chaofan Cao：got his M.S degree in 2018 at China Medical University. Then he joined the Respiratory Department of the Second Affiliated Hospital of Shenyang Medical College as an attending physician. His research interests include chronic airway disease, lung function, and respiratory endoscopy
      • Guixian Xiao：graduated from the Medical School of Tongji University in 1989. Head of respiratory Department of the Second Affiliated Hospital of Shenyang Medical College. Her research interests include bronchial asthma and chronic obstructive pulmonary disease
      • Yao Lu：got his M.S and Ph.D. degree in 2020 at the University of Science and Technology Beijing. Then he joined the State Key Laboratory of Automotive Safety and Energy at Tsinghua University as an assistant research fellow. His research interests include smart lithium-ion batteries and smart cell sensors
      • Corresponding author: workchaofan@163.com; yaolu@mail.tsinghua.edu.cn
      • Received Date: 2022-06-30
      • Revised Date: 2022-07-25
        • Available Online: 2022-09-08

      Catalog

        Journal of Semiconductors © 2017 All Rights Reserved   京ICP备05085259号-2

        /

        DownLoad:  Full-Size Img  PowerPoint
        Return
        Return