Light Emission Enhancement of (C<sub>3</sub>H<sub>10</sub>N)<sub>4</sub>Pb<sub>1–<i>x</i></sub>Mn<sub><i>x</i></sub>Br<sub>6</sub> Metal-Halide Powders by the Dielectric Confinement Effect of a Nanosized Water Layer
Tongtong Kou, Qilin Wei, Wenyong Jia, Tong Chang, Chengyu Peng, Yi Liang, Bingsuo Zou
Abstract
ion doping concentrations were synthesized by mechanochemical methods, giving broadband white light emission with a photoluminescence quantum yield of 36.1% at room temperature, which turn green with a much larger intensity at 80 K. Interestingly, its emission converted from white to red after 100 °C treatments and turned back to white again when exposed to moist air for a while. This emission variation was caused by the adsorbed water layer on the surface of product powders via the dielectric confinement. The red emission from no water powders is identified to occur from the Mn ferromagnetic pair in point-shared octahedral sites, while the broadband white emission originated from the surface water-assisted dielectric confinement and surface polarization which combine the self-trapped excitons and d-d transitions of Mn ions and Mn pairs in the product. Moreover, this white emission can transform into green color at 80 K with a much stronger intensity, caused by the even efficient surface dielectric confinement by the adsorbed frozen water layer. This special compound has the advantages of simple preparation, low cost, and good stability and even contains water molecule in the air, giving a near-perfect white emission, with CIE of (0.33, 0.35) and correlated color temperatures at around 5733 K, which may be used for different applications such as sensing, solid-state lighting, and display.