Tuning the Growth Process of Perovskite Single Crystal for Enhanced X-ray Detection Stability

Organic–inorganic halide perovskite single crystals with exceptional optoelectronic properties have become some of the most promising candidates for ionizing radiation detection. However, the existence of ion migration could cause collapse of the crystal interior and still hinder the realization of stable detection devices. As the most economical and convenient way to obtain large single crystals, the traditional inverse temperature crystallization (ITC) method with an accelerating growth pathway could induce the generation of more defects and aggravate the ion migration. In this study, we formulated a strategy to mitigate the growth acceleration phenomenon by incorporating an intermediate state within the ITC system through the introduction of benzylammonium iodide (BAI). BAI is capable of coordinating with the perovskite crystal's surface, thereby retarding the pace of growth. The grown single crystal of MA0.9GA0.1PbI3 (MA = methylammonium, GA = guanidinium) shows optimized defect density with the ion migration suppressed successfully. The fabricated X-ray detection device demonstrates an outstanding sensitivity of 9.19 × 105 μC Gyair–1 cm–2 and exceptional stability. It exhibits a remarkably low dark current drift of 4.50 × 10–7 nA cm–1 V–1 s–1 under a high bias of 330 V/cm during continuous operation over 30,000 s. This reduction is nearly 1 order of magnitude compared to other methods. Moreover, the device achieves a 3-fold enhancement in X-ray dose tolerance while maintaining 80% of its original sensitivity.