Growth, structural, optical and electronic transport properties of tetragonal CH₃NH₃SnBr₃ perovskite single crystals

The structural and electronic transport properties of tetragonal CH₃NH₃SnBr₃ single crystals (T-MASnBr₃ SCs) are rarely reported. In this study, we synthesized T-MASnBr₃ single crystals by volatilizing DMF solvent at room temperature. The crystal system and space group of the T-MASnBr₃ SC are tetragonal and P4/mmm, respectively. In addition, the nitrogen atom in the methylamine group exhibits position disorder. The band gap of the T-MASnBr₃ SC was determined to be 2.07 eV using the Tauc plot. Six fluorescence peaks and a lifetime up to 10 microseconds were observed in the steady-state fluorescence spectra and time-resolved fluorescence spectra of the T-MASnBr₃ SC, respectively. The carrier mobility (electron) of T-MASnBr₃ was 321 cm² V^-1 s^-1. The curve of ln(square resistance) against T^-1 was a straight line. The value of the activation energy (E_a) was 5421 J mol^-1. The stability of the T-MASnBr₃ SC was good before 473 K. The results indicate that T-MASnBr₃ SCs have promising applications in the field of temperature sensors.