In this work, a two-step metal organic chemical vapor deposition (MOCVD) method was applied for growing β-Ga₂O₃ film on c-plane sapphire. Optimized buffer layer growth temperature (T_B) was found at 700 °C and the β-Ga₂O₃ film with full width at half maximum (FWHM) of 0.66° was achieved. A metal?semiconductor?metal (MSM) solar-blind photodetector (PD) was fabricated based on the β-Ga₂O₃ film. Ultrahigh responsivity of 1422 A/W @ 254 nm and photo-to-dark current ratio (PDCR) of 10⁶ at 10 V bias were obtained. The detectivity of 2.5 × 10¹⁵ Jones proved that the photodetector has outstanding performance in detecting weak signals. Moreover, the photodetector exhibited superior wavelength selectivity with rejection ratio (R_{250 nm}/R_{400 nm}) of 10⁵. These results indicate that the two-step method is a promising approach for preparation of high-quality β-Ga₂O₃ films for high-performance solar-blind photodetectors.

由于硫系玻璃具有良好的光学性质，在非线性光学等方面研究广泛，但基于硫系玻璃光电探测器的相关研究却很少。本文利用真空共热蒸发技术制备了不同掺银比例的硫系玻璃薄膜作为半导体膜层结构，并设计构建了金属-绝缘体-半导体结构的自供电光电探测器，探究了该光电探测器的响应光谱范围。结果表明，该探测器对可见光到近红外区域的光均有响应。针对掺银硫系玻璃光电探测器在635 nm波长激光下，研究了探测器响应电压与激发功率之间的关系。当激光功率小于10 mW时，探测器响应电压与激发功率线性相关；当激光功率大于10 mW时，探测器响应电压逐渐饱和。探测器的上升和衰减时间分别为3.932 s和1.522 s。本研究为硫系玻璃材料在自供电光电探测器领域的应用提供了证明。

为了实现在无外部供能下对紫外光的有效探测，基于Ag修饰的Bi₂O₃纳米块（Ag/Bi₂O₃）纳米块制备了自供能紫外探测器。通过煅烧法制备Bi₂O₃纳米块，随后采用室温溶液法在其表面沉积Ag纳米粒子，进而成功制备了Ag/Bi₂O₃纳米块，且对所制备样品的晶体结构和微观形貌等进行了表征。结果表明，Ag/Bi₂O₃纳米块的平均尺寸约为1 μm，且Ag纳米粒子随机分布在Bi₂O₃纳米块表面。将涂覆Ag/Bi₂O₃纳米块的FTO作为工作电极，并进一步构建了自供能紫外探测器。在365 nm的紫外光照射下，Ag/Bi₂O₃纳米块紫外探测器能在零偏压下实现对紫外光的快速检测，这证实其具有自供能特性。相比于Bi₂O₃纳米块紫外探测器，Ag/Bi₂O₃纳米块紫外探测器的光电流得到明显提升，上升和下降时间分别缩短至29.1 ms和40.2 ms，并具有良好的循环稳定性。

为了获得高性能和低成本的氧化锌（ZnO）基紫外光探测器，使用Ga掺杂ZnO（ZnO∶Ga）作为光敏层，采用水热法合成了不同Ga掺杂浓度ZnO∶Ga微米棒，Ga与Zn的原子比分别为0%（未掺杂），0.5%，1%，2%和4%。使用X射线衍射仪（XRD）测试所有样品的晶体结构，发现它们都为六方纤锌矿结构的ZnO。采用扫描电子显微镜（SEM）观察它们的形貌，都呈现棒状结构。进一步，制备叉指图案氟掺杂的氧化锡（FTO）导电玻璃基底，将不同Ga掺杂浓度ZnO∶Ga微米棒分别涂覆在FTO上，得到5种简单结构的紫外光探测器，系统研究了它们的性能。结果表明：所有ZnO∶Ga微米棒紫外光探测器对365 nm紫外光表现出良好的响应。其中，1% Ga掺杂ZnO∶Ga微米棒紫外光探测器性能最佳，经计算，在365 nm波长处，它的响应度、增益和比探测率分别为13.13 A/W （5 V），44.63 （5 V），3.31×10¹² Jones，响应时间和衰减时间分别为12.3 s和36.4 s。说明在ZnO微米棒中进行合适Ga掺杂能有效提高紫外光探测器的性能。该研究有助于基于ZnO∶Ga材料的紫外光探测器及相关器件发展。

Narrowband photodetection is an important measurement technique for material analysis and sensing, for example, nondispersive infrared sensing technique. Both photoactive material engineering and nanophotonic filtering schemes have been explored to realize wavelength-selective photodetection, while most devices have a responsive bandwidth larger than 2% of the operating wavelength, limiting sensing performance. Near-infrared photodetection with a bandwidth of less than 0.2% of the operating wavelength was demonstrated experimentally in Au/Si Schottky nanojunctions. A minimum linewidth of photoelectric response down to 2.6 nm was obtained at a wavelength of 1550 nm by carefully tailing the absorptive and radiative loss in the nanostructures. Multiple functions were achieved on chip with the corrugated Au film, including narrowband resonance, light harvesting for sensing and photodetection, and electrodes for hot electron emission. Benefiting from such a unity integration with in situ photoelectric conversion of the optical sensing signal and the ultranarrowband resonance, self-contained on-chip biosensing via simple intensity interrogation was demonstrated with a limit of detection down to 0.0047% in concentration for glucose solution and 150 ng / mL for rabbit IgG. Promising potential of this technique is expected for the applications in on-site sensing, spectroscopy, spectral imaging, etc.

Organic–inorganic hybrid perovskite formamidinium lead bromide nanosheet (FAPbBr₃ NS) is regarded as a superior substance used to construct optoelectronic devices. However, its uncontrollable stability seriously affects its application in the field of photodetectors. In this paper, FAPbBr₃ is combined with cadmium sulfide nanobelt (CdS NB) to construct a hybrid device that greatly improves the stability and performance of the photodetector. The response of the FAPbBr₃ NS/CdS NB detector under 490 nm light illumination reaches 5712 A/W, while the response of the FAPbBr₃ photodetector under equivalent conditions is only 25.45 A/W. The photocurrent of the FAPbBr₃ NS/CdS NB photodetector is nearly 80.25% of the initial device after exposure to air for 60 days. The difference in electric field distribution between the single material device and the composite device is simulated by the finite-difference time-domain method. It shows the advantages of composite devices in photoconductive gain and directly promotes the hybrid device performance. This paper presents a new possibility for high stability, fast response photodetectors.

In this paper, we demonstrate nBn InAs/InAsSb type II superlattice (T2SL) photodetectors with AlAsSb as the barrier that targets mid-wavelength infrared (MWIR) detection. To improve operating temperature and suppress dark current, a specific Sb soaking technique was employed to improve the interface abruptness of the superlattice with device passivation using a SiO2 layer. These result in ultralow dark current density of 6.28×10-6A/cm2 and 0.31A/cm2 under -600mV at 97 K and 297 K, respectively, which is lower than most reported InAs/InAsSb-based MWIR photodetectors. Corresponding resistance area product values of 3.20×104Ω·cm2 and 1.32Ω·cm2 were obtained at 97 K and 297 K. A peak responsivity of 0.39 A/W with a cutoff wavelength around 5.5 µm and a peak detectivity of 2.1×109cm·Hz1/2/W were obtained at a high operating temperature up to 237 K.