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In Situ Formed Gradient Bandgap‐Tunable Perovskite for Ultrahigh‐Speed Color/Spectrum‐Sensitive Photodetectors via Electron‐Donor Control
Author(s) -
Sun Haoxuan,
Tian Wei,
Wang Xianfu,
Deng Kaimo,
Xiong Jie,
Li Liang
Publication year - 2020
Publication title -
advanced materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 10.707
H-Index - 527
eISSN - 1521-4095
pISSN - 0935-9648
DOI - 10.1002/adma.201908108
Subject(s) - photodetector , materials science , optoelectronics , photodetection , nanosecond , quantum efficiency , band gap , perovskite (structure) , detector , optics , laser , physics , chemical engineering , engineering
Integration of various photodetectors with different light‐sensitive materials and detection capacity is an inevitable way to achieve entire color/spectrum detection. However, the uneven capacity of each photodetector would drag the overall performance behind, especially the response speed. A response time down to nanosecond level has not previously been reported for a filter‐free color/spectrum‐sensitive photodetector, as far as is known. Here, a self‐powered filterless color‐sensitive photodetection array based on an in situ formed gradient perovskite absorber film with continuously tunable bandgap is demonstrated. Ultrahigh‐speed response at nanosecond level is achieved in all the ingredient photodetectors. The junction capacitance being influenced by carrier concentration in the absorber is identified to be responsible for the detection speed. Without any optic or mechanical supporting system, the designed color detector exhibits an external quantum efficiency (EQE) up to 94% and a high spectral resolution of around 80 nm for the whole visible spectrum. This work offers a guidance to achieve fast response of perovskite‐based photodetectors from the point of view of carrier‐donor control and demonstrates a new avenue to establish color‐sensitive photodetectors/spectrometers.