Improved Low‐Temperature Solution‐Growth of CsPbBr_3‐nCl_n Single Crystals for X‐Ray Detection

Abstract

The dark current drift caused by severe ion migration in allinorganic perovskite CsPbBr 3 degrades the stability of X-ray detection performance under a high electric field. The halogen doping is an effective method to improve the properties of the perovskites. In this work, the all-inorganic Cl-doped perovskites CsPbBr 3-n Cl n (n = 0, 0.1 and 0.5) single crystals were grown by a modified low-temperature inverse temperature crystallization (ITC) method with the growth temperature lower than the phase transition point. The trap density decreased to 3.05 × 10 10 cm À 3 and the carrier mobility increased to 124.75 cm 2 V À 1 s À 1 for the optimum component of CsPbBr 2.9 Cl 0.1 . Furthermore, by designing the detector with an asymmetric electrode configuration, CsPbBr 2.9 Cl 0.1 detector showed super low dark current and an outstanding hard X-ray induced photoresponse under a high voltage of 200 V. Consequently, the CsPbBr 2.9 Cl 0.1 perovskite detector delivers a high sensitivity (5593.24 μC Gy air À 1 cm À 2 ) and a low detection limit (0.68 μGy air s À 1 ). Our low temperature solution grown Cl-doped all-inorganic perovskite single crystals efficiently improve the photoelectric properties and enhance the X-ray detection performance.

Low Trap Density Para-F Substituted 2D PEA 2 PbX 4 (X = Cl, Br, I) Single Crystals with Tunable Optoelectrical Properties and High Sensitive X-Ray Detector Performance

“…Many factors should be considered to fabricate goodperformance X-ray detectors, such as the mechanical and atmospheric stability, absorption coefficient, detection area, etc. A large number of literatures have demonstrated the potential of perovskite single crystal materials for X-ray detectors previously, and the devices all show good performance [52][53][54][55]. In order to explore the specific effects of F substitution on the device performance, the corresponding X-ray detectors were prepared and tested.…”

Progress of Metal Halide Perovskite Crystals From a Crystal Growth Point of View

“…The trap density of CsPbBr 2.9 Cl 0.1 crystal by the VB method is almost two times larger (7.96 × 10 10 cm −3 ) than the crystal grown from this low temperature ITC method. [ 113 ] High‐quality MAPbBr 3 perovskite single crystals, with lateral dimension as large as 2 inch, have been grown by a small temperature gradient (2 °C per day) in the ITC method to keep the growth within the optimal single‐crystal‐growth (OSCG) region between the N – T and S – T curves to limit extraneous nucleation. [ 14 ]…”

Liquid-Phase Epitaxial Growth of Large-Area MAPbBr3–nCln/CsPbBr3 Perovskite Single-Crystal Heterojunction for Enhancing Sensitivity and Stability of X-ray Detector

“…The main causes of ion migration include crystal defects, such as vacancies and inversions in 3D perovskites, and low ion activation energies in 3D perovskites, i.e., ions easily overcome potential barriers and migrate to adjacent locations under the action of an applied electric field. Several strategies have been proposed to suppress ion migration in halide perovskites, such as passivating crystal defects, ,, improving the quality of single crystals, − and pre-applying reverse voltage suppression. ,− However, despite the excellent defect tolerance of halide perovskites for carrier transport, surface Schottky defects provide channels for ion migration, degrading the stability of devices constructed using these perovskites . Therefore, one of the most commonly adopted strategies for addressing this problem is passivating the surfaces (interfaces) of polycrystalline perovskites.…”