A high-efficiency photodetector consisting of colloidal PbS quantum dots (QDs) and single-layer graphene was prepared in this research. In the early stage, PbS QDs were synthesized and characterized, and the results showed that the product conformed with the characteristics of high-quality PbS QDs. Afterwards, the photodetector was derived through steps, including the photolithography and etching of indium tin oxide (ITO) electrodes and the graphene active region, as well as the spin coating and ligand substitution of the PbS QDs. After application testing, the photodetector, which was prepared in this research, exhibited outstanding properties. Under visible and near-infrared light, the highest responsivities were up to 202 A/W and 183 mA/W, respectively, and the highest detectivities were up to 2.24 × 10¹¹ Jones and 2.47 × 10⁸ Jones, respectively, with light densities of 0.56 mW/cm² and 1.22 W/cm², respectively. In addition to these results, the response of the device and the rise and fall times for the on/off illumination cycles showed its superior performance, and the fastest response times were approximately 0.03 s and 1.0 s for the rise and fall times, respectively. All the results illustrated that the photodetector based on PbS and graphene, which was prepared in this research, possesses the potential to be applied in reality.

Photodetectors (PDs) are the core component of multiple commercial optical sensing systems. Currently, the detection of ultra-weak ultraviolet (UV) optical signals is becoming increasingly important for wide range of applications in civil and military industries. Due to its wide band gap, low cost, and long-term stability, titanium dioxide (TiO ₂ ) is an attractive material for UV photodetection. A kind of low-cost TiO ₂ nanomaterial (named as P25) manufactured by flame hydrolysis is an easily available commercial material. However, a low-cost and high-sensitivity UV PD based on P25 has not been achieved until now. Here, a hybrid UV PD with monolayer CVD graphene covered by a thin film of P25 quantum dots was prepared for the first time, and its responsivity was approximately 10 ⁵ A W ⁻¹ at 365 nm wavelength. The response time and recovery time of the UV PD were 32.6 s and 34 s, respectively. Strong light absorption and photocontrolled oxygen adsorption of the P25 layer resulted in high UV sensitivity. The UV PDs proposed in this work have great potential for commercialization due to their low cost and high sensitivity.

Long term stability, high responsivity, and fast response speed are essential for the commercialization of graphene photodetectors (GPDs). In this work, a parylene/graphene UV photodetector with long term stability, ultrahigh responsivity and fast response speed, is demonstrated. Parylene as a stable physical and chemical insulating layer reduces the environmental sensitivity of graphene, and enhances the performances of GPDs. In addition, utilizing bilayer electrodes reduces the buckling and damage of graphene after transferring. The parylene/graphene UV photodetector exhibits an ultrahigh responsivity of 5.82 × 10⁵ AW⁻¹ under 325 nm light irradiation at 1 V bias. Additionally, it shows a fast response speed with a rise time of 80 μs and a fall time of 17 μs, and a long term stability at 405 nm wavelength which is absent in the device without parylene. The parylene/graphene UV photodetector possesses superior performances. This paves the way for the commercial application of the high-performance graphene hybrid photodetectors, and provides a practical method for maintaining the long term stability of two dimensional (2D) materials.

This study aims to explore simple preparation methods for high-quality SiO 2 aerogel film and their potential applications in infrared thermal radiation detectors. By utilizing a layer of nanoscale gold particles (Au NPs) to release the film stress during the spin-coating and drying process, we obtained SiO 2 aerogel film with uniform porosity, high adhesion strength, smooth surface, and excellent thermal insulation effect, with a measured thermal conductivity of 0.018W/mK. Further, we applied the SiO 2 aerogel film as a thermal barrier layer in microbolometer, experimentally obtaining a temperature coefficient (TCR) of 2.38%/K, a maximum voltage responsivity of 2.2×10 4 V/W, a thermal response time of 0.17 ms, and a detectivity of 3.6×10 7 cmHz 1/2 /W. Notably, the device was manufactured using a CMOScompatible process technology, which not only ensured low thermal conductivity but also enhanced device stability, simplified the fabrication process, reduced manufacturing costs, and improved yield, making it particularly suitable for large-scale batch array preparation.