Precursor Engineering for Solution Method-Grown Spectroscopy-Grade CsPbBr3 Crystals with High Energy Resolution

A CsPbBr3single crystal exhibits great potentials in X-ray/gamma-rayspectroscopy and imaging. Here, an inverse temperature crystallization (ITC) methodwith modified precursor composition is proposed to prepare CsPbBr3single crystals.The introduction of adduct PbBr2middot2DMSO, synthesized by the antisolvent vapor-assisted crystallization method, in the precursor solution gives rise to superiorcrystallization with a lower impurity concentration and higher resistivity of 6.37x109 Omega middotcm, as well as a higher hole mobility (50.7 cm2middotV-1middots-1). Furthermore, a low darkcurrent of 2.3 nA is obtained at a bias of-100 V based on an as-grown crystal with athickness of 1 mm, according to the asymmetric Au/CsPbBr3/Sn structure. Theresulting asymmetric planar detectors achieve the high peak-to-valley ratio pulse heightspectra with an energy resolution of 7.66%, illuminated by an uncollimated241Am@5.5MeV alpha particle. Simultaneously, an energy resolution of 13.5% is realized whenirradiated by a 59.5 keV241Am gamma-ray source at room temperature. The thermallystimulated current (TSC) spectra indicate that the density of deep energy-level trap issignificantly reduced in the CsPbBr3crystals grown by PbBr2middot2DMSO-modified precursor solution, which is consistent with the highperformance in radiation detection.