Chemical Potential Diagram Guided Rational Tuning of Electrical Properties: A Case Study of CsPbBr₃ for X‐ray Detection

Abstract

Controlling the carrier polarity and concentration underlies most electronic and optoelectronic devices. However, for the intensively studied lead halide perovskites, the doping tunability is inefficient. In this work, taking CsPbBr3 as an example, it is revealed that the coexistence of metallic Pb or CsBr3/Br2, rather than the precursor ratio, can provide Pb‐rich/Br‐poor or Br‐rich/Pb‐poor chemical conditions, enabling the tunability of electrical properties from weak n‐type, intrinsic, to moderate p‐type. Experimentally, under Br2‐exposure treatment, a shift of the Fermi level as large as 1.00 eV is achieved, which is one of the highest value among all kinds of doping methods. The X‐ray detector based on the intrinsic CsPbBr3 exhibits excellent performance, with a negligible dark‐current drift of 7.1 × 10−4 nA cm−1 s−1 V−1, a low detection limit of 103.6 nGyair s−1, and a high sensitivity of 9085 μC Gyair−1 cm−2. This work provides a critical understanding and guidance for tuning the electrical properties of lead halide perovskites, which establishes good foundations for achieving intrinsic perovskite semiconductors and also constructing potential homojunction devices.

Competing Energy Transfer-Modulated Dual Emission in Mn2+-Doped Cs2NaTbCl6 Rare-Earth Double Perovskites

“…Lead halide perovskites of ABX 3 (A = MA + , Cs + ; B = Pb 2+ , X = Cl – , Br – , I – ) have been widely studied due to their promising optoelectronic applications such as such as solar cells, − light-emitting diodes, − lasers, − X-ray detectors, − and scintillators. , However, lead-based halide perovskites are often unstable and easily hydrolyzed. − Meanwhile, the toxicity of lead limits their applications . Thus, it is urgent to develop alternative lead-free perovskites with photoelectric properties similar to those of lead-based perovskites.…”

High‐Quality 0D Cs4PbBr6‐Based Dense Wafer for High‐Sensitivity X‐Ray Detection and High‐Resolution Imaging in Harsh Environment

“…[32,33] According to a previous study, CsBr 3 could provide a Br-rich environment, which benefits Br − vacancy restraint. [34] In light of the above analysis, the crystal structure of Cs 4 PbBr 6 is diagramed in Figure 1i and Cif 1, where [PbBr 6 ] 4− octahedra array was isolated by Cs + ion.…”

Highly Crystalline CsPbBr3 Perovskite Nanoparticles for Liquid Crystal Displays

“…As shown in Figure a,b, the single peak at 402.2 eV of the N 1s core level observed in the spectrum of NCs with DD 10 AB post-treatment gives clear evidence for the existence of DDA + on the NC surface . The shoulder peaks locked at 136.6 and 141.4 eV are attributed to the undercoordinated Pb for pristine-CsPbBr 3 NCs, which would lead to the formation of Br vacancies . On the contrary, it is observed that the shoulder entirely disappears in the spectrum of DD 10 AB-CsPbBr 3 NCs, indicating that Pb 2+ is coordinated with Br – stemming from DD 10 AB, and thus, Br vacancy is effectively passivated, resulting in an improved stability of NCs with higher PLQY.…”