Improved Stability and Photoluminescence Yield of Mn2+-Doped CH3NH3PbCl3 Perovskite Nanocrystals

Organic–inorganic CH3NH3PbCl3 perovskite nanocrystals (PNCs) doped with Mn2+, CH3NH3PbxMn1−xCl3, have been successfully prepared using a reprecipitation method at room temperature. Structural and morphological characterizations reveal that the CH3NH3PbxMn1−xCl3 PNCs with cubic phase transforms from particles to cubes and increases in size from 16.2 ± 4.4 nm in average diameter to 25.3 ± 7.2 nm in cubic length after the addition of Mn2+ precursor. The CH3NH3PbxMn1−xCl3 PNCs exhibit a weak exciton emission at ~405 nm with a low absolute quantum yield (QY) of around 0.4%, but a strong Mn2+ dopant emission at ~610 nm with a high QY of around 15.2%, resulting from efficient energy transfer from the PNC host to the Mn2+ dopant via the T1→A1 transition. In addition, the thermal and air stability of CH3NH3PbxMn1−xCl3 PNCs are improved due to the passivation with (3-aminopropyl) triethoxysilane (APTES), which is important for applications such as light emitting diodes (LEDs).