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Schottky Barrier‐Controlled Black Phosphorus/Perovskite Phototransistors with Ultrahigh Sensitivity and Fast Response
Author(s) -
Zou Xuming,
Li Yuanzhe,
Tang Guanqi,
You Peng,
Yan Feng
Publication year - 2019
Publication title -
small
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.785
H-Index - 236
eISSN - 1613-6829
pISSN - 1613-6810
DOI - 10.1002/smll.201901004
Subject(s) - responsivity , schottky barrier , optoelectronics , materials science , perovskite (structure) , photodiode , photodetector , schottky diode , metal–semiconductor junction , depletion region , black phosphorus , layer (electronics) , rise time , active layer , schottky effect , voltage , nanotechnology , semiconductor , chemistry , electrical engineering , diode , engineering , crystallography , thin film transistor
Phototransistors are recognized as highly sensitive photodetectors owing to their high gain induced by a photogating effect. However, the response speed of a typical phototransistor is rather slow due to the long lifetime of trapped carriers in the channel. Here, a novel Schottky barrier‐controlled phototransistor that shows ultrahigh sensitivity as well as a fast response speed is reported. The device is based on a channel of few‐layer black phosphorous modified with a MAPbI 3− x Cl x perovskite layer, whose channel current is limited by the Schottky barrier at the source electrode. The photoresponse speed of the device can be tuned by changing the drain voltage, which is attributed to a field‐assisted detrapping process of electrons in the perovskite layer close to the Schottky barrier. Under optimal conditions, the device exhibits a high responsivity of 10 6 –10 8 A W −1 , an ultrahigh specific detectivity up to 9 × 10 13 Jones, and a response time of ≈10 ms.