Low Bandgap 2D Perovskite Single Crystal with Anomalous‐large Charges/ions Collection Ratio for Ultra‐sensitive and Stable X‐ray Detectors

Abstract

The low-dimensional halide perovskites have attracted increasing attention due to their improved moisture stability, reduced defects, and suppressed ions migration in many optoelectronic devices such as solar cells, light-emitting diodes, X-ray detectors, and so on. However, they are still limited by their large band gap and short charge carriers' diffusion length. Here, we demonstrate that the introduction of metal ions into organic interlayers of two-dimensional (2D) perovskite by cross-linking the copper paddle-wheel cluster-based lead bromide ([Cu(O 2 CÀ (CH 2 ) 3 À NH 3 ) 2 ]PbBr 4 ) perovskite single crystals with coordination bonds can not only significantly reduce the perovskite band gap to 0.96 eV to boost the X-ray induced charge carriers, but can also selectively improve the charge carriers' transport along the out-of-plane direction and blocking the ions motion paths. The [Cu(O 2 CÀ (CH 2 ) 3 À NH 3 ) 2 ]PbBr 4 single-crystal device can reach a record charges/ions collection ratio of 1.69 × 10 18 � 4.7 % μGy air À 1 s, and exhibit a large sensitivity of 1.14 × 10 5 � 7% μC Gy air À 1 cm À 2 with the lowest detectable dose rate of 56 nGy air s À 1 under 120 keV X-rays irradiation. In addition, [Cu-(O 2 CÀ (CH 2 ) 3 À NH 3 ) 2 ]PbBr 4 single-crystal detector exposed to the air without any encapsulation shows excellent X-ray imaging capability with long-term operational stability without any attenuation of 120 days.

2D Perovskite Single‐Crystalline Photodetector with Large Linear Dynamic Range for UV Weak‐Light Imaging

“…This can be attributed to the low conductivity of organic layers, which hinders carrier transport along the vertical direction. [ 46 ] These findings demonstrate that 2D PPB SCs have the potential to be utilized for polarized light detection after appropriate modification and further optimization.…”

Dimensional and Optoelectronic Tuning of Lead‐free Perovskite Cs3Bi2I9−nBrn Single Crystals for Enhanced Hard X‐ray Detection

“…As shown in Figure 7a, the 1/ f of CBI8B SC device is only 5.53×10 −15 A Hz −1/2 , which is lower than that of CPB (7.25×10 −15 A Hz −1/2 ) and commercial CZT (4.43×10 −13 A Hz −1/2 ). A lower noise current is conducive for low detection limits [3b,33] …”

Regulating the Stereoisomerism of Diammonium Cations to Construct Polar Dion-Jacobson Hybrid Perovskites for Self-Powered X-ray Detection

“…The photosensitive properties and high atomic number ( Z ) of lead-based HPs make them excellent in X-ray photodetectors. − At present, the application of DJ HPs constructed with different configurations of diammonium cations in the field of X-ray detection mainly relies on external bias driving operation, which greatly limits the application of photodetectors. For example, monolayer DJ HPs (4-aminobenzylamine)­PbI 4 , (3-amidinopyridine)­PbX 4 (X is halogen), and (1,4-butadiammonium)­PbI 4 , and bilayered DJ HPs (1,4-butanediamine)­CsPb 2 Br 7 and (3-(aminomethyl)­pyridinium)­(formamidinium)­Pb 2 I 7 are all used for X-ray detection under external bias.…”