Spectroscopic-grade single crystal detectors can register the energies of individual X-ray interactions enabling photon-counting systems with superior resolution over traditional photoconductive X-ray detection systems. Current technical challenges have limited the preparation of perovskite semiconductors for energy-discrimination X-ray photon-counting detection. Here, this work reports the deployment of a spectroscopic-grade CsPbBr3 Schottky detector under reverse bias for continuum hard X-ray detection in both the photocurrent and spectroscopic schemes. High surface barriers of ≈1 eV are formed by depositing solid bismuth and gold contacts. The spectroscopic response under a hard X-ray source is assessed in resolving the characteristic X-ray peak. The methodology in enhancing X-ray sensitivity by controlling the X-ray energies and flux, and voltage, is described. The X-ray sensitivity varies between a few tens to over 8000 μC Gyair−1 cm−2. The detectable dose rate of the CsPbBr3 detectors is as low as 0.02 nGyair s−1 in the energy discrimination configuration. Finally, the unbiased CsPbBr3 device forms a spontaneous contact potential difference of about 0.7 V enabling high quality of the CsPbBr3 single crystals to operate in “passive” self-powered X-ray detection mode and the X-ray sensitivity is estimated as 14 μC Gyair−1 cm−2. The great potential of spectroscopic-grade CsPbBr3 devices for X-ray photon-counting systems is anticipated in this work.
Bibliographical noteFunding Information:
This research was sponsored by the Defense Threat Reduction Agency (DTRA) as part of the Interaction of Ionizing Radiation with Matter University Research Alliance (IIRM‐URA) under contract number HDTRA1‐20‐2‐0002. This work made use of the Materials Processing and Microfabrication Facility supported by the MRSEC program of the National Science Foundation (DMR‐1720139) at the Materials Research Center of Northwestern University. Work at Argonne National Laboratory was supported by the Accelerator and Detector R&D program in Basic Energy Sciences’ Scientific User Facilities (SUF) Division at the Department of Energy.
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- Schottky barrier
- X-ray photon counting
- gamma-ray response
- perovskite semiconductor
- single crystal