Photophysical Pathways in Highly Sensitive Cs2AgBiBr6 Double‐Perovskite Single‐Crystal X‐Ray Detectors

• DOI: 10.1002/adma.201804450
• Publication Date: 2018-09-17T14:01:26Z
• Authors: Julian A. Steele; Weicheng Pan; Cristina Martin; Masoumeh Keshavarz; Elke Debroye; Haifeng Yuan; Subhasree Banerjee; Eduard Fron; Dries Jonckheere; Cheol Woong Kim; Wouter Baekelant; Guangda Niu; Jiang Tang; Johan Vanacken; Mark Van der Auwe...; Johan Hofkens; Maarten B. J. Roe...
• Keywords: X-ray detector; Crystal (programming language)

The sensitive detection of X-rays embodies an important research area, being motivated by a common desire to minimize the radiation doses required for detection. Among metal halide perovskites, double-perovskite Cs2 AgBiBr6 system has emerged as promising candidate X-rays, capable high X-ray stability and sensitivity (105 μC Gy-1 cm-2 ). Herein, photophysical pathways in single-crystal are detailed at both room (RT) liquid-nitrogen (LN2 T) temperatures, with emphasis made toward understanding carrier dynamics that influence sensitivity. This study draws upon several optical probes RT excitation model is developed which far from optimal, plagued large trap density fast free-carrier recombination pathways. Substantially improved operating conditions revealed 77 K, long fundamental lifetime (>1.5 µs) marked depopulation parasitic temperature dependence detecting device characterized strong monotonic enhancement cooling demonstrated, moving 316 988 near LN2 T. It concluded even modest cooling-via Peltier device-will facilitate substantial performance, ultimately lowering required.