Efficient Orange Emission in Mn<sup>2+</sup>-Doped Cs<sub>3</sub>Cd<sub>2</sub>Cl<sub>7</sub> Perovskites with Excellent Stability
Yilin Gao, Xinxin Han, Qilin Wei, Tong Chang, Yuanjie Chen, Bingsuo Zou, Sheng Cao, Jialong Zhao, Ruosheng Zeng
Abstract
Low-dimensional metal halides are attractive for applications in photodetectors, solid-state lighting, and solar cells, but poor stability is an obstacle that must be overcome in commercial applications. Herein, we successfully synthesized a Ruddlesden–Popper (RP)-phased perovskite Mn2+:Cs3Cd2Cl7 with high photoluminescence quantum yield (PLQY) and outstanding thermal and environmental stability by a solvothermal method. The pristine sample Cs3Cd2Cl7 exhibits a weak cyan broad emission centered at 510 nm with a low PLQY of ∼4%. Once Mn2+ ions are introduced into the host lattice, a bright orange emission peaking at 580 nm with a high PLQY of ∼74% was achieved, which is attributed to the efficient energy transfer from the host to Mn2+ ions and thus results in the 4T1 → 6A1 radiation transition of Mn2+ ions. The photoluminescence (PL) intensity and environmental stability of Mn2+:Cs3Cd2Cl7 can be further improved through A-site Rb alloying. Finally, an orange LED with outstanding color stability was fabricated on the basis of the Mn2+:Cs3Cd2Cl7. Our work successfully elucidates that dopant plays an integral role in tailoring optical properties.