This paper presents a design of single photon avalanche diode (SPAD) light detection and ranging (LiDAR) sensor with 128 × 128 pixels and 128 column-parallel time-to-analog-merged-analog-to-digital converts (TA-ADCs). Unlike the conventional TAC-based SPAD LiDAR sensor, in which the TAC and ADC are separately implemented, we propose to merge the TAC and ADC by sharing their capacitors, thus avoiding the analog readout noise of TAC’s output buffer, improving the conversion rate, and reducing chip area. The reverse start-stop logic is employed to reduce the power of the TA-ADC. Fabricated in a 180 nm CMOS process, our prototype sensor exhibits a timing resolution of 25 ps, a DNL of +0.30/−0.77 LSB, an INL of +1.41/−2.20 LSB, and a total power consumption of 190 mW. A flash LiDAR system based on this sensor demonstrates the function of 2D/3D imaging with 128 × 128 resolution, 25 kHz inter-frame rate, and sub-centimeter ranging precision.

Resistive random access memories (RRAMs) are emerging as a key enabling technology for cost-effective, energy-efficient and secure chips, especially in the framework of edge computing. In particular, their electrically programmable resistance has been widely exploited in several in-memory computing and neuromorphic architectures. By adjusting the applied voltages and compliance currents (I_C), RRAM devices can be programmed to multiple resistance states during set and reset procedures, enabling multilevel functionality. While the multilevel behavior of the reset phase is generally well captured by existing compact models, only a few account for the multilevel characteristics of the set operations. Moreover, such models are rarely validated against comprehensive experimental datasets capturing device dynamics across multiple timescales. In this work, we present a physics-based compact model that enhances the UniMORE RRAM framework by incorporating the dynamic lateral evolution of the conductive filament (CF), thereby enabling accurate simulation of set operations at varying I_C values. The model is calibrated to experimental data from IHP 130 nm 1T1R RRAM technology and reproduces device behavior across several operating conditions using a single set of parameters. The results highlight the potential of the proposed compact model in design optimization workflows of RRAM-based circuits.

The continuous progress in thin film materials and devices has greatly promoted the development in the field of flexible electronics. As one of the most common thin film devices, thin film transistors (TFTs) are significant building blocks for flexible platforms. Flexible oxide-based TFTs are well compatible with flexible electronic systems due to low process temperature, high carrier mobility, and good uniformity. The present article is a review of the recent progress and major trends in the field of flexible oxide-based thin film transistors. First, an introduction of flexible electronics and flexible oxide-based thin film transistors is given. Next, we introduce oxide semiconductor materials and various flexible oxide-based TFTs classified by substrate materials including polymer plastics, paper sheets, metal foils, and flexible thin glass. Afterwards, applications of flexible oxide-based TFTs including bendable sensors, memories, circuits, and displays are presented. Finally, we give conclusions and a prospect for possible development trends.

Although perovskite solar cells containing methylamine cation can show high power conversion efficiency, stability is a concern. Here, methylamine-free perovskite material Cs_xFA_1–xPbI₃ was synthesized by a one-step method. In addition, we incorporated smaller cadmium ions into mixed perovskite lattice to partially replace Pb ions to address the excessive internal strain in perovskite structure. We have found that the introduction of Cd can improve the crystallinity and the charge carrier lifetime of perovskite films. Consequently, a power conversion efficiency as high as 20.59% was achieved. More importantly, the devices retained 94% of their initial efficiency under 1200 h of continuous illumination.

In the present work, zinc oxide (ZnO) and silver (Ag) doped ZnO nanostructures are synthesized using a hydrothermal method. Structural quality of the products is attested using X-ray diffraction, which confirms the hexagonal wurtzite structure of pure ZnO and Ag-doped ZnO nanostructures. XRD further confirms the crystallite orientation along the c-axis, (101) plane. The field emission scanning electron microscope study reveals the change in shape of the synthesized ZnO particles from hexagonal nanoparticles to needle-shaped nanostructures for 3 wt% Ag-doped ZnO. The optical band gaps and lattice strain of nanostructures is increased significantly with the increase of doping concentration of Ag in ZnO nanostructure. The antimicrobial activity of synthesized nanostructures has been evaluated against the gram-positive human pathogenic bacteria, Staphylococcus aureus via an agarose gel diffusion test. The maximum value of zone of inhibition (22 mm) is achieved for 3 wt% Ag-doped ZnO nanostructure and it clearly demonstrates the remarkable antibacterial activity.

Silicon photonics is an emerging competitive solution for next-generation scalable data communications in different application areas as high-speed data communication is constrained by electrical interconnects. Optical interconnects based on silicon photonics can be used in intra/inter-chip interconnects, board-to-board interconnects, short-reach communications in datacenters, supercomputers and long-haul optical transmissions. In this paper, we present an overview of recent progress in silicon optoelectronic devices and optoelectronic integrated circuits(OEICs) based on a complementary metal-oxide-semiconductor-compatible process, and focus on our research contributions. The silicon optoelectronic devices and OEICs show good characteristics, which are expected to benefit several application domains, including communication, sensing, computing and nonlinear systems.

The AC-electronic and dielectric properties of different phthalocyanine films (ZnPc, CuPc, FePc, and H₂Pc) were investigated over a wide range of temperature. Both real and imaginary parts of the dielectric constant (ε=ε₁-iε₂) were found to be influenced by temperature and frequency. Qualitatively the behavior was the same for those compounds; however, the central atom, film thickness, and the electrode type play an important role in the variation of their values.The relaxation time, τ, was strongly frequency-dependent at all temperatures and low frequencies, while a weak dependency is observed at higher frequencies. The relaxation activation energy was derived from the slopes of the fitted lines of ln τ and the reciprocal of the temperature (1/T). The values of the activation energy were accounted for the hopping process at low temperatures, while a thermally activated conduction process was dominant at higher temperatures.The maximum barrier height, W_m, was found to be temperature and frequency dependent for all phthalocyanine compounds. The value W_m depends greatly on the nature of the central atom and electrode material type. The correlated barrier hopping model was found to be the appropriate mechanism to describe the charge carrier's transport in phthalocyanine films.

Bulk single-crystal aluminum nitride (BSC AlN) substrates are known to be ideal platforms for constructing high-power and DUV optoelectronic nitride devices. However, high-quality epitaxial growth of nitride films on BSC AlN and related characterization is still far from being well studied. The challenges and uncertainties in doing accurate thermal characterization on such heterostructures are not fully recognized. In this study, we successfully fabricated a buffer-free thin GaN/AlN heterostructure on a BSC AlN substrate via metal−organic chemical vapor deposition (MOCVD) technology. This heterostructure consists of a 140 nm-thick AlN homoepitaxial layer and a 480 nm-thick GaN epitaxial layer. Characterization results indicate that the prepared heterojunction has excellent crystal quality and smooth surface morphology. To accurately obtain the thermophysical parameters of the heterostructure, this study employed broadband frequency domain thermoreflectance (BB-FDTR) technology, and careful measurements with detailed data analysis were demonstrated. In addition to showing the feasibility of epitaxial growth of high-quality thin film GaN directly on BSC AlN substrates, this study also provides key experimental data for evaluating the heat dissipation advantages of GaN/AlN heterostructures.