Iodine doping of CsPbBr 3 : toward highly stable and clean perovskite single crystals for optoelectronic applications

ABSTRACTCaesium-based mixed halide perovskite single crystals, CsPbBr3-xIx, are shown to be good candidates for many optoelectronic applications under ambient conditions. The partial substitution of iodine into the bromine sites of CsPbBr3 single crystal makes attractive effects in optical and structural properties as well as their thermal and phase stability. Herein, the Inverse Temperature Crystallization (ITC) method has been utilised to grow high-quality, large, and single-phase single crystals of CsPbBr2.4I0.6 perovskites. The iodine doping is found to result in improved purity, thermal, phase, and atmospheric stability of the single crystal and helped to tune the band gap. Further, there is a conspicuous decrease in the defect density with iodine doping. Thus the present study establishes iodine doping as a facile route to grow CsPbBr3 single crystals with overall stability and improved defect density with a broad absorption spectrum, that point toward extended optoelectronic and photovoltaic applications.KEYWORDS: Mixed halide perovskiteInorganic lead halide perovskiteThermal stabilitySingle crystalOptoelectronic applicationsCrystal growth AcknowledgmentsThe authors are thankful to The Centre for Materials Characterization, NIT Calicut for the help and support during the work and to The ANERT (Agency for New and Renewable Energy Research & Technology), Government of Kerala, provided assistance for the same (Project No. ANERT-TECH/11/2019-S(NEP)).Disclosure statementNo potential conflict of interest was reported by the authors.