Currently, the global 5G network, cloud computing, and data center industries are experiencing rapid development. The continuous growth of data center traffic has driven the vigorous progress in high-speed optical transceivers for optical interconnection within data centers. The electro-absorption modulated laser (EML), which is widely used in optical fiber communications, data centers, and high-speed data transmission systems, represents a high-performance photoelectric conversion device. Compared to traditional directly modulated lasers (DMLs), EMLs demonstrate lower frequency chirp and higher modulation bandwidth, enabling support for higher data rates and longer transmission distances. This article introduces the composition, working principles, manufacturing processes, and applications of EMLs. It reviews the progress on advanced indium phosphide (InP)-based EML devices from research institutions worldwide, while summarizing and comparing data transmission rates and key technical approaches across various studies.

To address the escalating demand for high-mobility transparent and conductive oxide (TCO) films in heterojunction solar cells, multiple components doped In₂O₃ targets were proposed. The In₂O₃ targets incorporating 1 wt.% CeO₂, Ta₂O₅, and TiO₂ were sintered under different sintering temperatures and times. All the targets show the cubic bixbyite phase of In₂O₃. The microstructure illustrates densely packed fine grains and uniform elemental distribution. Notably, increasing the sintering temperature and holding time contributes to effective pore elimination within the targets. A relative density of greater than 99.5% is obtained for the targets sintered at 1500 °C for 4 and 6 h, and the corresponding optimum resistivity decreases from 1.068 × 10⁻³ to 9.73 × 10⁻⁴ Ω·cm. These results provide the experimental basis of fabricating In₂O₃-based targets for depositing high mobility TCO films by magnetron sputtering.

As organic thin film transistors (OTFTs) are set to play a crucial role in flexible and cost-effective electronic applications, this paper investigates a high-mobility 6,13-bis(triisopropylsilylethynyl) pentacene (TIPS-pentacene) OTFT for use in flexible electronics. The development of such high-mobility devices necessitates precise device modeling to support technology optimisation and circuit design. The details of numerical simulation technique is discussed, in which, the electrical behavior of the device is well captured by fine tuning basic semiconductor equations. This technology computer-aided design (TCAD) has been validated with exprimental data. In addition, we have discussed about compact model fitting of the devices as well as parameter extraction procedure employed. This includes verification of Silvaco ATLAS finite element method (FEM) based results against experimental data gained from fabricated OTFT devices. Simulations for p-type TFT-based inverter are also performed to assess the performance of compact model in simple circuit simulation.

Avalanche photodiode (APD) is a kind of photodetector with important applications in optical communication, light detection and ranging (LIDAR) and other fields. APDs fabricated using the recently developed AlGaAsSb as the multiplication material exhibit excellent noise performance. In this work, we report a low-noise separate absorption, grading, charge, and multiplication (SAGCM) InGaAs/AlGaAsSb APD operating at 1550 nm. A double-mesa structure was fabricated to reduce the dark current. Numerical simulations were conducted to compare two different mesa-structured APDs. By analyzing the electric field distribution, it was found that the electric field at the edge of the multiplication region in the double-mesa APD is nearly 100 kV/cm lower than that of the single-mesa structure. Experimental results demonstrate that after device punch-through, the double-mesa APD’s dark current can be reduced by up to four times compared to the single-mesa APD. Quantitative analysis of the dark current components in the AlGaAsSb APD further confirms that the low sidewall electric field in the double-mesa structure effectively suppresses the trap-assisted tunneling. Additionally, noise measurements indicate a k-value of approximately 0.014, which is significantly lower than that of traditional multiplication materials. This work provides preliminary validation for further performance improvements in low noise and low dark current AlGaAsSb APDs.

To optimize turn on velocity of the SiC LIMS, we proposed a new structure for the LIMS that incorporates an optimized n⁺ layer and a multi-light triggered electrode design for the anode. The chip size is 5.5 mm × 5.5 mm in dimension. The experiment results indicate that the saturation laser energy required to trigger the prepared SiC LIMS has been decreased from 1.8 mJ to 40 μJ, with the forward blocking voltage of the prepared SiC LIMSs capable of withstanding over 7000 V. The leakage current is about 0.3 μA at room temperature, and the output current density achieves 4.25 kA/cm² (with di/dt larger than 20 kA/μs).

The optical soliton characteristics of GaSb-based ~2 μm wavelength integrated optical chips have broad application prospects in optoelectronic fields such as optical communications, infrared countermeasures, and gas environment monitoring. In the research of two-section integrated optical chips, more attention is paid to their passive mode-locked characteristics. The ability of its structure to generate stable soliton transmission has not yet been studied, which will limit its further application in high-performance near-mid infrared optoelectronic technology. In this paper, we design and prepare a GaSb-based ~2 μm wavelength two-section integrated semiconductor laser chip structure, and test and analyze its related properties of soliton, including power−injection current−voltage (P−I−V), temperature and mode-locked characteristics. Experimental results show that the chip can achieve stable mode-locked operation at nearly ~2 μm wavelength and present the working characteristics of near optical soliton states and multi-peak optical soliton states. By comparing and analyzing the measured optical pulse sequence curve with the numerical fitting based on the pure fourth order soliton approximation solution, it is confirmed that the two-section integrated optical chip structure can generate stable transmission of multi-peak optical soliton. This provides a research direction for developing near-mid infrared mode-locked integrated optical chips with high-performance property of optical soliton.

In this paper, a planar junction mid-wavelength infrared (MWIR) photodetector based on an InAs/GaSb type-Ⅱ superlattices (T2SLs) is reported. The Intrinsic-πMN superlattices was grown by the molecular beam epitaxy (MBE), followed with a ZnS layer grown by the chemical vapor deposition (CVD). The p-type contact layer was constructed by thermal diffusion in the undoped superlattices. The Zinc atom was successfully realised into the superlattice and a PπMN T2SL structure was constructed. Furthermore, the effects of different diffusion temperatures on the dark current performance of the devices were researched. The 50% cut-off wavelength of the photodetector is 5.26 μm at 77 K with 0 V bias. The minimum dark current density is 8.67 × 10⁻⁵ A/cm² and the maximum quantum efficiency of 42.5%, and the maximum detectivity reaches 3.90 × 10¹⁰ cm·Hz^1/2/W at 77 K. The 640 × 512 focal plane arrays (FPA) based on the planner junction were fabricated afterwards. The FPA achieves a noise equivalent temperature difference (NETD) of 539 mK.

As the development of single-junction solar cells reaches a bottleneck, tandem solar cells have emerged as a critical pathway to further enhance power conversion efficiency. Among them, monolithic perovskite/silicon heterojunction tandem solar cells are currently the fastest-growing technology, achieving the highest efficiencies at relatively low costs. The interconnecting layer, which connects the two sub-cells, plays a crucial role in tandem cell performance. It collects electrons and holes from the respective sub-cells and facilitates recombination and tunneling at the interface. Therefore, the properties of the interconnecting layer are pivotal to the overall device performance. In this work, we applied statistical analysis and machine learning algorithms to systematically analyze the interconnecting layer. A comprehensive dataset on interconnecting layer parameters was established, and predictive modeling was performed using Lasso linear regression, random forest, and multilayer perceptron (a type of neural network). The analysis revealed key feature importance for experimental parameters, providing valuable insights into the application of interconnecting layers in perovskite/silicon heterojunction tandem solar cells. The final optimized interconnecting layer can achieve a proof-of-concept efficiency of 38.17%, providing guidance and direction for the development of monolithic perovskite/silicon tandem solar cells.