All-Oxide Transparent Photodetector Array for Ultrafast Response through Self-Powered Excitonic Photovoltage Operation |
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Authors: | Shuvaraj Ghosh Malkeshkumar Patel Junsik Lee Joondong Kim |
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Affiliation: | Photoelectric and Energy Device Application Lab (PEDAL) and Multidisciplinary Core Institute for Future Energies (MCIFE), Incheon National University, Incheon, 22012 South Korea |
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Abstract: | Can photodetectors be transparent and operate in self-powered mode? Is it possible to achieve invisible electronics, independent of the external power supply system, for on-site applications? Here, a ZnO/NiO heterojunction-based high-functional transparent ultraviolet (UV) photodetector operating in the self-powered photovoltaic mode with outstanding responsivity and detectivity values of 6.9 A W−1 and 8.0 × 1012 Jones, respectively, is reported. The highest IUV/Idark value of 8.9 × 104 is attained at a wavelength of 385 nm, together with a very small dark current value of 9.15 × 10−12 A. A large-scale sputtering method is adopted to deposit the heterostructure of n-ZnO and p-NiO sequentially. This deposition instinctively forms an abrupt junction, resulting in a high-quality heterojunction device. Moreover, developing a ZnO/NiO-heterojunction–based 4 × 5 matrix array with an output photovoltage of 4.5 V is preferred for integrating photodetectors into sensing and imaging systems. This transparent UV photodetector exhibits the fastest photo-response time (83 ns) reported for array configurations, which is achieved using an exciton-induced photovoltage based on a neutral donor–bound exciton. Overall, this study provides a simple method for achieving a high-performance large-scale transparent UV photodetector with a self-powered array configuration. |
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Keywords: | exciton photodetector arrays transient photovoltage transparent ultraviolet photodetectors ZnO/NiO heterojunction |
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