This study analysed GaN nanophosphors based white light-emitting diodes (WLEDs) with ultraviolet (UV) excitation. Graphene quantum dots (GQDs) used as a charge transfer medium to enhance the performance in terms of luminous efficacy and colour quality. The improvement in colour rendering and colour temperature has been observed with the increase in injection current. The luminous efficacy of radiation also gets improved with injection current and maximises up to 255 lm/W at 260 mA along with 90 colour rendering index and 7100 K correlated colour temperature. Mapping of higher surface temperature for GQD-based devices shows a better thermal stability, indicating the good heat dissipation capability of GQDs because of excellent thermal conductivity. Therefore, proposed WLEDs were found more competent with improved thermal quenching of phosphors for rare-earth-free solid-state lighting as compared to the blue chip-excited yellow phosphors.

中文翻译：

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GaN磷光体转换的白色发光二极管具有高发光效率和改善的热稳定性

这项研究分析了具有紫外线（UV）激发作用的基于GaN纳米磷光体的白光发光二极管（WLED）。石墨烯量子点（GQD）用作电荷转移介质，以提高发光效率和颜色质量的性能。随着注入电流的增加，显色性和色温得到了改善。辐射的发光效率也随着注入电流而得到改善，并在260 mA时达到最大255 lm / W，同时具有90显色指数和7100 K相关色温。基于GQD的设备的较高表面温度的映射显示了更好的热稳定性，这表明GQD具有出色的导热性，因此具有良好的散热能力。因此，