Coupled Gel/Seeded Growth of Cs2AgBiBr6 Single Crystals for Radiation Detection

The all-inorganic lead free Cs2AgBiBr6 perovskite represents a highly promising environment-friendly radiation detector material.The first attempt to grow Cs2AgBiBr6 single crystals using the unique gel growth method is reported in this study.This technique enables controlled reagent diffusion in a gel medium at room temperature, fostering the growth of visible single crystals.It offers advantages over conventional methods, leading to fewer equilibrium and non-equilibrium defects and simplified execution.Interestingly, the as-grown crystals exhibited variations in size and colors within the gel matrix, indicating the influence of Bi solutes in Bi-poor and Bi-rich Cs2AgBiBr6 crystals.Once the crystals were confirmed by powder xray diffraction, a series of comprehensive material characterizations was performed.The resistivity of Cs2AgBiBr6 single crystals was measured at 1.12x10 7 cm.Trap density analysis yielded a value of 2.82 x10 10 cm -3 .The charge carrier mobility was determined to be 32.9 cm 2 V -1 S -1 , suggesting the suitability for radiation detector applications.Additional growth optimization is going on and further characterization will be reported during the presentation.Our work helps accelerate the development of lead-free perovskite materials toward radiation detector applications.