High‐Performance Low‐Voltage‐Driven Phototransistors through CsPbBr3–2D Crystal van der Waals Heterojunctions. Issue 16 (10th June 2018)

• Record Type: Journal Article
• Authors: Huo, Chengxue; Liu, Xuhai; Wang, Ziming; Song, Xiufeng; Zeng, Haibo
• Is Part Of: Advanced optical materials. Volume 6:Issue 16(2018)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2018-06-10
• Subjects: 2D materials -- perovskites -- phototransistors -- van der Waals epitaxy; Optical materials -- Periodicals; Photonics -- Periodicals; 620.11295
• DOI: 10.1002/adom.201800152
• Languages: English
• ISSNs: 2195-1071

Abstract

Abstract: Combining halide perovskites and 2D materials to form heterojunctions is a potential excellent strategy to design high‐performance phototransistors. However, a standard perovskite/2D material heterojunction is not fully realized, because either of the active material usually directly bridges across the opposite metal electrodes in the transistor platform. Here, phototransistors are fabricated based on high‐quality van der Waals grown CsPbBr3 and MoS2, in which CsPbBr3 and MoS2 are overlapped only within the transistor channel. The phototransistors based on this standard CsPbBr3 /MoS2 heterojunction exhibit excellent optical detection ability and field‐effect characteristics at a drain–source voltage as small as 0.5 V. The rise and fall times of the phototransistor are 2.5 and 1.8 ms, respectively. The hole mobility is calculated to be 0.08 cm 2 V −1 s −1 in darkness, and 0.28 cm 2 V −1 s −1 under the 442 nm laser illumination. All of the measurements are conducted at room temperature in ambient air, indicating the excellent robustness of the CsPbBr3 /MoS2 heterojunction. This work provides a new strategy to minimize the device size by using low‐voltage‐driven, air‐stable perovskite/2D material heterojunctions. Abstract : Van‐der‐Waals heterojunctions based on two‐dimensional (2D) materials and thin halide perovskite single crystals can effectively combine the advantages of both 2D materials and halide perovskites. The optimized optical and electrical tuning of CsPbBr3 /MoS2 band alignment can effectively separate the holes and electrons excited by photons, which leads to a low‐voltage‐operated phototransistor.