Weak light imaging has drawn more and more attention because of its promising potential for practical applications in security monitoring and space exploration. In this work, all-inorganic Cs2AgBiBr6 double perovskite...Weak light imaging has drawn more and more attention because of its promising potential for practical applications in security monitoring and space exploration. In this work, all-inorganic Cs2AgBiBr6 double perovskite-based self-powered photodetectors containing inorganic copper thiocyanate(CuSCN) as hole-transport layers(HTLs) are successfully fabricated and applied for weak light imaging,which is the first report on the weak light imaging application of all-inorganic lead-free perovskite photodetectors. CuSCN films with favorable optical property and hole extraction capability are prepared via a cost efficient and fast solvent removal method, demonstrating the potential for high-performance perovskite-based devices as transparent components. It is revealed that the band alignment of the device is effectively optimized with the presence of CuSCN HTLs,which can availably transport holes while block electrons at the Cs2AgBiBr6/CuSCN interface, resulting in remarkable improvement of photoresponse performance. The responsivity and detectivity are 0.34 A W^-1 and 1.03×10^13 Jones,respectively. In particular, the light current has a boost of almost 10 times. Furthermore, the photodetectors are integrated into a self-built light detection imaging system utilizing the focused laser scanning imaging mode. With illumination of as low as 5 nW cm^-2(405 nm), the image involving graphics and words with a size of 5 cm×5 cm can still be distinctly recognized. These results suggest the promising potential of all-inorganic perovskite-based devices for weak light detection and imaging applications.展开更多
We propose ghost imaging(GI)with deep learning to improve detection speed.GI,which uses an illumination light with random patterns and a single-pixel detector,is correlation-based and thus suitable for detecting weak ...We propose ghost imaging(GI)with deep learning to improve detection speed.GI,which uses an illumination light with random patterns and a single-pixel detector,is correlation-based and thus suitable for detecting weak light.However,its detection time is too long for practical inspection.To overcome this problem,we applied a convolutional neural network that was constructed based on a classification of the causes of ghost image degradation.A feasibility experiment showed that when using a digital mirror device projector and a photodiode,the proposed method improved the quality of ghost images.展开更多
基金supported by the National Natural Science Foundation of China (51772135)the Ministry of Education of China (6141A02022516)+4 种基金the Fundamental Research Funds for the Central Universities (11619103)China Postdoctoral Science Foundation (2019M663376)Guangdong Province Higher Vocational Colleges & Schools Pearl River Scholar Funded Scheme (2017)the Natural Science Foundation of Guangdong Province, China (2017A020215135 and 2018A030310659)the Science and Technology Program of Guangzhou, China (201804010432)。
文摘Weak light imaging has drawn more and more attention because of its promising potential for practical applications in security monitoring and space exploration. In this work, all-inorganic Cs2AgBiBr6 double perovskite-based self-powered photodetectors containing inorganic copper thiocyanate(CuSCN) as hole-transport layers(HTLs) are successfully fabricated and applied for weak light imaging,which is the first report on the weak light imaging application of all-inorganic lead-free perovskite photodetectors. CuSCN films with favorable optical property and hole extraction capability are prepared via a cost efficient and fast solvent removal method, demonstrating the potential for high-performance perovskite-based devices as transparent components. It is revealed that the band alignment of the device is effectively optimized with the presence of CuSCN HTLs,which can availably transport holes while block electrons at the Cs2AgBiBr6/CuSCN interface, resulting in remarkable improvement of photoresponse performance. The responsivity and detectivity are 0.34 A W^-1 and 1.03×10^13 Jones,respectively. In particular, the light current has a boost of almost 10 times. Furthermore, the photodetectors are integrated into a self-built light detection imaging system utilizing the focused laser scanning imaging mode. With illumination of as low as 5 nW cm^-2(405 nm), the image involving graphics and words with a size of 5 cm×5 cm can still be distinctly recognized. These results suggest the promising potential of all-inorganic perovskite-based devices for weak light detection and imaging applications.
文摘We propose ghost imaging(GI)with deep learning to improve detection speed.GI,which uses an illumination light with random patterns and a single-pixel detector,is correlation-based and thus suitable for detecting weak light.However,its detection time is too long for practical inspection.To overcome this problem,we applied a convolutional neural network that was constructed based on a classification of the causes of ghost image degradation.A feasibility experiment showed that when using a digital mirror device projector and a photodiode,the proposed method improved the quality of ghost images.
