Fine-Tuning Single-Source White-Light Emission from All-Inorganic Corrugated 2D Antimony-Halide Perovskite

摘要

Corrugated 2D antimony-halide perovskites such as Cs_3Sb_2Cl_9 (CSC) arepromising candidates for single-source white-light emission due to their ultrabroadbandspectra. However, CSC has a serious luminescence quenchingphenomenon due to inadequate confinement of excitons. By the homovalentsubstitution of trivalent antimony cation Sb~(3+) by a small amount of trivalent rareearth (RE) cations RE~(3+), the photoluminescence intensities from high-qualityCs_3(Sb_(1?x)RE_x)_2Cl_9 (CSRC) (RE = Ce, Sm, Nd, Y, Er, etc.) films at room temperature(RT) are over two orders of magnitude higher than that of CSC film. Especially,the photoluminescence quantum yield (PLQY) for the Cs_3(Sb_(0.995)Er_(0.005))_2Cl_9 filmis 9.5% at RT, which is much higher than A_3B_2X_9 perovskites previously reportedfor single-source white-light lighting. Furthermore, the Cs_3(Sb_(0.995)Er_(0.005))_2Cl_9film exhibits an ultra-broadband emission with the full width at half maximumreaching 554 meV at RT, resulting in a “warm” white-light with the CIE coordinate(0.33, 0.46) and the correlated color temperature of 5450 K. The PLQY enhancementcan be considered as the fact that a high activation energy by bandgapwidening effect and Type-I-like “straddling” band alignment between Cs_3Sb_2Cl_9and Cs_3Er_2Cl_9 lead to reducing nonradiative losses and increasing radiativerecombination channels. Meanwhile, the spectral broadening can be consideredto be attributed to strong effect of electron–phonon interaction.