Double perovskite Cs2AgBiBr6 radiation sensor: synthesis and characterization of single crystals

摘要

Single crystals of lead-free halide double perovskite Cs2AgBiBr6 sensor material manifest a remarkable potential for application in radiation detection and imaging. In this study, the purity and crystallinity of solution-grown Cs2AgBiBr6 single crystals with cubic Fm (3) over barm symmetry have been corroborated by powder XRD measurements, while the single crystal XRD patterns reveal the dominant {111} lattice planes parallel to the sample surfaces. A wider range of lower resistivity values (10(6)-10(9) omega cm) was obtained from the I-V measurements compared to the 1.55 x 10(9)-6.65 x 10(10) omega cm values from the van der Pauw method, which is typically higher for the Ag than for the carbon paint electrodes. Charge-carrier mobility values estimated from the SCLC method for the carbon paint-Cs2AgBiBr6 (1.90-4.82 cm(2)V(-1) s(-1)) and the Ag-Cs2AgBiBr6 (0.58-4.54 cm(2)V(-1) s(-1)) including the density of trap states (10(9)-10(10) cm(-3)) are comparable. Similar values of 1.89 cm(2)V(-1) s(-1) and 2.36 cm(2)V(-1) s(-1) are derived from the Hall effect measurements for a sample with carbon and Ag electrodes, respectively. The key electrical parameters including the X-ray photoresponse measurements indicate that the Cs2AgBiBr6 samples synthesized in this study satisfy requirements for radiation sensors.