Identifying Carrier Behavior in Ultrathin Indirect-Bandgap CsPbX3 Nanocrystal Films for Use in UV/Visible-Blind High-Energy Detectors
Alwadai, Norah M.
Roqan, Iman S.
KAUST DepartmentElectron Microscopy
Material Science and Engineering Program
Physical Science and Engineering (PSE) Division
Semiconductor and Material Spectroscopy (SMS) Laboratory
KAUST Grant NumberBAS/1/1319-01-01
Online Publication Date2020-10
Print Publication Date2020-10
Embargo End Date2021-10-02
Permanent link to this recordhttp://hdl.handle.net/10754/665425
MetadataShow full item record
AbstractHigh-energy radiation detectors such as X-ray detectors with low light photoresponse characteristics are used for several applications including, space, medical, and military devices. Here, an indirect bandgap inorganic perovskite-based X-ray detector is reported. The indirect bandgap nature of perovskite materials is revealed through optical characterizations, time-resolved photoluminescence (TRPL), and theoretical simulations, demonstrating that the differences in temperature-dependent carrier lifetime related to CsPbX3 (X = Br, I) perovskite composition are due to the changes in the bandgap structure. TRPL, theoretical analyses, and X-ray radiation measurements reveal that the high response of the UV/visible-blind yellow-phase CsPbI3 under high-energy X-ray exposure is attributed to the nature of the indirect bandgap structure of CsPbX3. The yellow-phase CsPbI3-based X-ray detector achieves a relatively high sensitivity of 83.6 μCGyair−1 cm−2 (under 1.7 mGyair s−1 at an electron field of 0.17 V μm−1 used for medical diagnostics) although the active layer is based solely on an ultrathin (≈6.6 μm) CsPbI3 nanocrystal film, exceeding the values obtained for commercial X-ray detectors, and further confirming good material quality. This CsPbX3 X-ray detector is sufficient for cost-effective device miniaturization based on a simple design.
CitationXin, B., Alaal, N., Mitra, S., Subahi, A., Pak, Y., Almalawi, D., … Roqan, I. S. (2020). Identifying Carrier Behavior in Ultrathin Indirect-Bandgap CsPbX3 Nanocrystal Films for Use in UV/Visible-Blind High-Energy Detectors. Small, 2004513. doi:10.1002/smll.202004513
SponsorsThis work was financially supported by the King Abdullah University of Science and Technology (KAUST) baseline funding (BAS/1/1319-01-01). The authors thank the KAUST Medical Center (KMC) located at the KAUST campus for providing their X-ray facilities for carrying out the measurements.