利用ITO微纳结构提高石墨烯紫外LED光提取效率

为了改善因为铟锡氧化物(ITO)薄层对紫外光具有高吸收率，从而导致石墨烯紫外LED低光提取效率(LEE)问题，采用ITO微纳结构(矩形和三角形)作为石墨烯紫外LED缓冲层的方法，利用时域有限差分法，对ITO微纳结构进行优化，并对石墨烯紫外LED进行了理论分析。结果表明，当矩形微纳结构厚度为160nm、占空比为0.7、周期为220nm时，在单层石墨烯下紫外LED的LEE可达10.668%;利用矩形微结构作为插入层相比于利用ITO薄层作为插入层的单层石墨烯紫外LED提高了45.06%；而当三角微纳结构在最优参量时，石墨烯紫外LED的LEE仅有6.64%，明显低于ITO薄层石墨紫外LED。该研究可为后续制备高光功率的紫外LED提供理论基础。

Improve the extraction efficiency of graphene

In order to improve the low light extraction efficiency(LEE) of graphene UV light-emitting diode (LED) due to the high absorption of indium tin oxide (ITO) thin layer to UV light, the ITO micro nano structure (rectangle and triangle) was used as the buffer layer of graphene UV LED. The ITO micro nano structure was optimized and graphene UV LED was theoretically analyzed by the finite difference time domain method. The results show that when the thickness, duty cycle and period of rectangular micro nano structure are 160nm and 0.7, 220nm respectively, the LEE of UV LED can reach 10.668% under single graphene. The use of rectangular micro structure as the insertion layer is 45.06% higher than that of ITO thin layer as the insertion layer, while when the triangular micro nano structure is in the optimal parameters, the LEE of graphene UV LED is only 6.64%, significantly lower than that of ITO thin layer. This study can provide a theoretical basis for the subsequent preparation of high-power UV LED.