Metal halide perovskites (MHPs) are frontrunners among solution-processable materials for lightweight, large-area and flexible optoelectronics. These materials, with the general chemical formula AMX3, are structurally complex, undergoing multiple polymorph transitions...

The low-frequency Raman spectra of metal-halide perovskites are reported using a combination of a 976 nm laser and nanoconfinement to stabilize the crystals against temperature-induced polymorph transitions and humidity-induced degradation.

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