Photophysical Pathways in Highly Sensitive Cs2AgBiBr6 Double-Perovskite Single-Crystal X-Ray Detectors
| Autor: | Johan Vanacken, Mark Van der Auweraer, Jiang Tang, Cheol Woong Kim, Subhasree Banerjee, Eduard Fron, Julian A. Steele, Cristina Martin, Johan Hofkens, Wouter Baekelant, Guangda Niu, Dries Jonckheere, Maarten B. J. Roeffaers, Masoumeh Keshavarz, Haifeng Yuan, Weicheng Pan, Elke Debroye |
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| Jazyk: | angličtina |
| Rok vydání: | 2018 |
| Předmět: |
Technology
X-ray detection Materials science Chemistry Multidisciplinary Materials Science X-ray detector Materials Science Multidisciplinary SEMICONDUCTOR 02 engineering and technology Radiation 010402 general chemistry double perovskite PHOTONS 01 natural sciences Physics Applied Thermoelectric effect Cs2AgBiBr6 General Materials Science Sensitivity (control systems) Nanoscience & Nanotechnology photophysics Science & Technology business.industry Chemistry Physical Mechanical Engineering Physics Carrier lifetime HALIDE 021001 nanoscience & nanotechnology CARRIERS 0104 chemical sciences Chemistry Physics Condensed Matter Mechanics of Materials Physical Sciences Optoelectronics Science & Technology - Other Topics 0210 nano-technology business Single crystal Excitation Recombination |
| Popis: | 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, the double-perovskite Cs2 AgBiBr6 system has emerged as a promising candidate for the detection of X-rays, capable of high X-ray stability and sensitivity (105 μC Gy-1 cm-2 ). Herein, the important photophysical pathways in single-crystal Cs2 AgBiBr6 are detailed at both room (RT) and liquid-nitrogen (LN2 T) temperatures, with emphasis made toward understanding the carrier dynamics that influence X-ray sensitivity. This study draws upon several optical probes and an RT excitation model is developed which is far from optimal, being plagued by a large trap density and fast free-carrier recombination pathways. Substantially improved operating conditions are revealed at 77 K, with a long fundamental carrier lifetime (>1.5 µs) and a marked depopulation of parasitic recombination pathways. The temperature dependence of a single-crystal Cs2 AgBiBr6 X-ray detecting device is characterized and a strong and monotonic enhancement to the X-ray sensitivity upon cooling is demonstrated, moving from 316 μC Gy-1 cm-2 at RT to 988 μC Gy-1 cm-2 near LN2 T. It is concluded that even modest cooling-via a Peltier device-will facilitate a substantial enhancement in device performance, ultimately lowering the radiation doses required. ispartof: ADVANCED MATERIALS vol:30 issue:46 ispartof: location:Germany status: published |
| Databáze: | OpenAIRE |
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