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Updated: Jun 20, 2026
Monovalent Cation Doping of CH3NH3PbI3 for Efficient Perovskite Solar Cells
Published on: March 19, 2017
Stabilization of the Cubic Crystalline Phase in Organometal Halide Perovskite Quantum Dots via Surface Energy
Som Sarang1, Sara Bonabi Naghadeh2, Binbin Luo2
1School of Natural Sciences, University of California , Merced, California 95340, United States.
Abstract:
Surface functionalization of nanoscale materials has a significant impact on their properties. We have demonstrated the effect of different passivating ligands on the crystal phase of organometal halide perovskite quantum dots (PQDs). Using static and dynamic spectroscopy, we studied phase transitions in CH3NH3PbBr3 PQDs ligated with either octylaminebromide (P-OABr) or 3-aminopropyl triethoxysilane (P-APTES). Around 140 K, P-OABr underwent a structural phase transition from tetragonal to orthorhombic, established by the emergence of a higher energy band in the photoluminescence (PL) spectrum. This was not observed in P-APTES, despite cooling down to 20 K. Additionally, time-resolved and excitation power-dependent PL, as well as Raman spectroscopy over a range of 300-20 K, revealed that recombination rates and types of charge carriers involved are significantly different in P-APTES and P-OABr. Our findings highlight how aspects of PQD phase stabilization are linked to nanoscale morphology and the crystal phase diagram.
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