Elimination of Interfacial‐Electrochemical‐Reaction‐Induced Polarization in Perovskite Single Crystals for Ultrasensitive and Stable X‐Ray Detector Arrays. Issue 52 (22nd October 2021)

• Record Type: Journal Article
• Authors: Song, Yilong; Li, Liqi; Hao, Mingwei; Bi, Weihui; Wang, Anran; Kang, Yifei; Li, Hanming; Li, Xiaohui; Fang, Yanjun; Yang, Deren; Dong, Qingfeng
• Is Part Of: Advanced materials. Volume 33:Issue 52(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-10-22
• Subjects: imaging arrays -- interfacial electrochemical reaction -- perovskite single crystals -- X‐ray detectors; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adma.202103078
• Languages: English
• ISSNs: 0935-9648

Abstract

Abstract: Organic–inorganic halide perovskites have exhibited bright prospects in high‐sensitivity X‐ray detection. However, they generally suffer from the severe field‐driven polarization issue that remarkably deteriorates the detection performance. Here, it is demonstrated that the interfacial electrochemical reaction between Au electrodes and halogen in MAPbI3 single crystals (SCs) is the major source of the dark current polarization in the metal–semiconductor–metal (MSM)‐structured perovskite X‐ray detectors at the initial stage of biasing. By introducing the p‐ and n‐type charge transport layers to isolate the electrodes from contacting the SC surface, the polarization is fully eliminated under a large electric field up to 1000 V cm −1 . Moreover, the resultant lateral p–i–n heterojunction suppresses the dark current of the devices by nearly 3 orders of magnitude as compared to the MSM counterparts and therefore enables a high sensitivity of 5.2 × 10 6 µC Gy −1 air cm −2 and a record low X‐ray detection limit down to 0.1 nGyair s −1 . The excellent biasing stability and sensitivity of the devices allow to prepare the linear detector arrays for X‐ray imaging applications. Abstract : By introducing p‐ and n‐type charge transport layers in the coplanar‐structured perovskite X‐ray detector to isolate the contact between the electrode and the perovskite, the interfacial electrochemical‐reaction‐induced polarization is effectively suppressed under large electric field up to 1000 V cm −1, which results in superior device performance with a low X‐ray detection limit down to 0.1 nGyair s −1 .