Additive Engineering for Ambient Blade‐Coated CsPbBr ₃ Films Enabling High‐Performance Self‐Powered X‐Ray Detection

ABSTRACT Hybrid perovskite materials have recently emerged as a promising candidate in radiation detection research due to their superior charge carrier mobility and lower trap‐state density. While most perovskite X‐ray detectors typically rely on external bias for charge collection, the growing demand for efficient and energy‐saving perovskite X‐ray detectors has spurred extensive interest in self‐powered devices, which offer high‐performance, low power consumption, and enhanced portability. To date, most high‐performance self‐powered X‐ray detectors rely on secondary crystal growth via post‐deposition immersion in saturated solutions. Herein, we report a facile additive engineering strategy employing 4‐trifluoromethyphenylammonium iodide (CF ₃ PhAI) to modulate perovskite crystallization, enabling single‐step fabrication of microcrystalline CsPbBr ₃ films with grain sizes up to 38.6 µm. This approach effectively passivates defects and suppresses ion migration in CsPbBr ₃ , reducing dark current drift by nearly two orders of magnitude from 4.135 × 10 ⁻¹² to 4.167 × 10 ⁻¹⁴ A s ⁻¹ . Moreover, the incorporation of a low‐work‐function aluminum (Al) top electrode significantly enhances the built‐in electric field, yielding a remarkable zero‐bias sensitivity of 1.3 × 10 ³ µC Gy _air ⁻¹ cm ⁻² . This work accelerates the development of high‐performance self‐powered perovskite X‐ray detectors toward practical applications.