Improving the Performance and High‐Field Stability of FAPbBr₃ Single Crystals in X‐Ray Detection with Chenodeoxycholic Acid Additive

Abstract

Suppressing the ion migration is critical and urgent for the future applications of perovskite single crystals.Ion migration in perovskite SCs is mainly caused by the ion movements such as organic cations and halide ions through the vacancies under the light or external field. [21][22][23] Many methods including doping halogen atom, [10,17,24] A-site substitution, [5,25,26] organic macromolecule addition in precursor solution, [27] and surface passivation, [28][29][30] were proposed to either reduce the channels of ion movements or increase the activation energy of ions. Huang et al. [10] reported a dopant-compensated MAPbBr 2.94 Cl 0.06 alloy with a reduced leakage current and current drift, and the resulting device exhibited a resolution of 6.5% for 137 Cs γ-ray detection. Tao et al. [17] demonstrated that doping iodine in the CsPbBr 3 melt can effectively reduce the current drift in CsPbBr 3−x I x SCs under the high field of 5000 V cm −1 and achieve a high sensitivity of 6.3 × 10 4 µC Gy air −1 cm −2 (CsPbBr 2.9 I 0.1 ) and a detection limit of 54 nGy air s −1 (CsPbBr 2 I) in X-ray detection. Yan et al. [25] proposed the A-and X-site substitution method to prepare FA 0.95 Cs 0.05 PbI 2.7 Br 0.3 single crystals, which demonstrated a great irradiation hardness at an accumulated dose of 200 krad and an excellent resistance to the humidity and the heat. Huang et al. [27] reported that a ligand-assisted solution process with 3-(decyldimethylammonio)-propane-sulfonate inner salt (DPSI) can significantly improve the dark current stability of MAPbI 3 SCs. The corresponding CH 3 NH 3 PbI 3 detectors achieved a superior sensitivity of (2.6 ± 0.4) × 10 6 µC Gy air −1 cm −2 and a detection limit of (5.0 ± 0.7) nGy air s −1 for 60 keV X-ray detection. Shao et al. [28] reported that the PEABr surface treatment of MAPbBr 3 SCs led to a performance improvement in X-ray detection and achieved a sensitivity of 15 280 µC Gy air −1 cm −2 and a detection limit of 87 nGy air s −1 under 5 V bias. These strategies can improve the dark current stability and the X-ray detection performance, paving the road for the commercial applications of perovskite SCs in optoelectric devices and X-ray detection.Among 3D perovskite SCs, FAPbBr 3 SCs exhibit promising stabilities in terms of the low dark current drift, high thermostability, and high phase stability. [11,21,31,32] Mohammed et al. [21] Organometal halide perovskite single crystals are one of the most promising radiation detection materials due to their unique advantages of high absorption coefficient, long carrier diffusion length, and low defect density. However, the severe ion migration in perovskites deteriorates the X-ray detection performance under longtime and high-field operating conditions. This work reports an effective additive of chenodeoxycholic acid (CDCA), which can suppress the ion migration and improve the performance and the operational stability of FAPbBr 3 single crystals (SCs) in X-ray detection significantl. The CDCA molecules in precursors effectively suppress the...

Growth mechanism of metal halide perovskite single crystals in solution

“…39 Furthermore, the presence of certain groups and carbon chain length characteristics in the additive contributes to the hydrophobicity and stability of the active layer in perovskite solar cells. 73–75 As shown in Fig. 4c, the conventional solvent ( e.g .…”

A Review on Covalent Organic Frameworks as Artificial Interface Layers for Li and Zn Metal Anodes in Rechargeable Batteries

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Synergistic crystallization regulation and defect passivation for growth of high-quality perovskite single crystals towards ultrasensitive X-ray detection

“…28–30 Introducing additives in the perovskite precursor solution has been reported for easily preparing high-quality SCs through reducing the crystal growth rate. 31,32 The working mechanism lies in the improved energy barrier due to the coordination of the passivator with undercoordinated ions on crystal surfaces. The surface anchored passivator could suppress the improper occupation of ions or the absence of suitable ions.…”