Luminescence properties of Mn-doped 2D organic-inorganic hybrid perovskites: Insights from (PPA)2PbBr4 perovskite

The incorporation of Mn2+ ions has been widely used to modulate optical properties of two-dimensional (2D) organic-inorganic hybrid perovskites (OIHPs). However, the luminescence mechanism of Mn2+ ions that is related to the A-site cations remains largely unexplored. Herein, we report the synthesis of a series of Mn-doped A2PbBr4 (A = C6H5(CH2)nNH3, n = 1,2,3,4,) 2D perovskites. The (C6H5(CH2)3NH3)2PbBr4 ((PPA)2PbBr4) 2D perovskite exhibited a maximum photoluminescence (PL) quantum yield of 67 %, a prolonged PL lifetime of 0.75 ms, and the highest energy transfer efficiency of 78.07 %. Furthermore, we systematically investigated the luminescence properties of Mn-doped (PPA)2PbBr4 perovskite with different Mn2+ concentrations. The temperature dependent PL spectra indicate a thermalized de-trap process of self-trapped exciton at high temperatures and the presence of permanently shallow defect states in highly doped samples with lower activation energy.