RESUMEN
Metal halide perovskites are promising optoelectronic materials due to their outstanding luminescent properties. However, the instability of perovskites has long been the bottleneck to their practical applications. Here Cs4PbBr6 nanocrystals based glass composite (Cs4PbBr6 NCs@glass) are successfully prepared, which displays green emission color (520 nm), narrow bandwidth (23 nm) and a near-unity photoluminescence quantum yield (PLQY). The H2O molecules permeating in the lattice of Cs4PbBr6 were found to be a crucial role in the subband energy emission. The Cs4PbBr6 NCs@glass has excellent emission stability; maintains 93 % of initial PL intensity after ultraviolet light irradiation for over 5000 h. In addition, by adjusting the halogen content, we have achieved tunable emission color from blue (450 nm) to green (520 nm) and red (670 nm) on Cs4PbX6 NCs@glass (X = Cl, Br, I), which covers up to 127 % of the National Television Systems Board (NTSC) standard system. Our finding indicates the commercial applications of perovskite materials in lighting and display.
RESUMEN
Artificial lighting consumes almost one-fifth of global electricity. As an efficient solid-state lighting technology, white light-emitting diodes (WLEDs) have received increasing attention. However, the white luminescence of the traditional WLEDs comes from multi-component emitters, which leads to complex device structure and unstable emitting color. Therefore, developing single-component materials with white-light electroluminescence is of significance for artificial lighting applications. Here, we fabricate single-component white-light electroluminescence devices based on an aromatic carbon nitride material and improve the performance of WLEDs by adjusting the carrier transport. The carbon nitride LEDs emit warm-white light, of which color coordinates and color temperature are (0.44, 0.52) and 3700 K. The optimized LEDs display a very low turn-on voltage of 3.2 V and achieve a milestone in the maximum luminance and external quantum efficiency of 1885 cd m-2 and 1.20%. Our findings demonstrate the low-cost carbon nitride materials have promising potential for single-component WLEDs application.