Inch-Sized Thin Metal Halide Perovskite Single-Crystal Wafers for Sensitive X-Ray Detection.

Anbo Feng,Wei Zhu,Xiuwei Fu,Shengdan Xie,Zhaolai Chen

doi:10.3389/fchem.2021.823868

Anbo Feng, Wei Zhu + Show 3 more

Open Access

https://doi.org/10.3389/fchem.2021.823868

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Abstract

Metal halide perovskite single crystals are a promising candidate for X-ray detection due to their large atomic number and high carrier mobility and lifetime. However, it is still challenging to grow large-area and thin single crystals directly onto substrates to meet real-world applications. In this work, millimeter-thick and inch-sized methylammonium lead tribromide (MAPbBr3) single-crystal wafers are grown directly on indium tin oxide (ITO) substrates through controlling the distance between solution surface and substrates. The single-crystal wafers are polished and treated with O3 to achieve smooth surface, lower trap density, and better electrical properties. X-ray detectors with a high sensitivity of 632 µC Gyair −1 cm−2 under –5 V and 525 µC Gyair −1 cm−2 under –1 V bias can be achieved. This work provides an effective way to fabricate substrate-integrated, large-area, and thickness-controlled perovskite single-crystal X-ray detectors, which is instructive for developing imaging application based on perovskite single crystals.

Highlights

In recent years, metal halide perovskite (MHP) materials have been demonstrated as promising candidates for sensitive X-ray detections due to their superior properties (Li Z et al, 2021), such as large atomic number, high carrier mobility and lifetime, and low-defect density (Wei et al, 2017; Cheng et al, 2019; Chen et al, 2019)
We report sensitive X-ray detectors made of millimeter-thick and inch-sized MAPbBr3 single-crystal wafers
Synthesis of Methylammonium Bromide (CH3NH3Br): CH3NH3Br was synthesized on the basis of the previously reported method in which hydrobromic acid (HBr) and CH3NH2 were reacted with the molar ratio of 1:1.2

Summary

Introduction

Metal halide perovskite (MHP) materials have been demonstrated as promising candidates for sensitive X-ray detections due to their superior properties (Li Z et al, 2021), such as large atomic number, high carrier mobility and lifetime, and low-defect density (Wei et al, 2017; Cheng et al, 2019; Chen et al, 2019). There are two kinds of perovskite X-ray detectors: direct and indirect detection modes (Zhou et al, 2020). Compared to indirect detection which converts X-ray to a light signal, the direct detection mode which converts X-ray to an electrical signal has larger spatial resolution and higher sensitivity (Basiricò et al, 2019). Α-Se detectors have low sensitivity and require high dose for imaging, which brings cancer risk to the patients (Kasap et al, 2000). The sensitivity of perovskite X-ray detectors are several orders of magnitude larger than that of commercial α-Se detectors, especially for hard X-ray (Wang et al, 2020; Deumel et al, 2021; Liu et al, 2021a; Peng et al, 2021)

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