为了提高倒装发光二极管(LED)的光提取效率, 提出在蓝宝石衬底出光面上制备一层SiO2介质光栅, 形成表面光栅倒装LED结构。利用RSOFT软件的CAD模块建立表面光栅倒装LED模型, 随后使用RSOFT软件的LED模块模拟并优化该表面光栅倒装LED。通过模拟优化和理论分析可得, 当p-GaN层厚度hp=220 nm, n-GaN层厚度hn=100 nm, 蓝宝石衬底厚度hs=130 nm, 光栅周期p=260 nm, 光栅厚度hg=20 nm, 光栅占空比f=0.02时, 表面光栅倒装LED的光提取效率可以达到49.12%, 相比于普通最优倒装LED的光提取效率(30.56%)提高了63%。本研究可为后续设计高光提取效率的LED提供参考, 同时亦可为制备器件提供理论指导。

In order to improve the light extraction efficiency of flip-chip light-emitting diode (LED), we propose to prepare a SiO2 dielectric grating on the sapphire substrate surface and form a surface grating flip-chip LED structure. The surface grating flip-chip LED model is established by the CAD module of RSOFT software. Then, the LED module of RSOFT software is used to simulate and optimize the surface grating flip-chip LED. Simulation optimization and theoretical analysis show that, when p-GaN layer thickness hp=220 nm, n-GaN layer thickness hn=100 nm, sapphire substrate thickness hs=130 nm, grating period p=260 nm, grating thickness hg=20 nm, grating duty cycle f=0.02, the light extraction efficiency of the surface grating flip-chip LED can reach to 49.12%, compared to the best normal flip-chip LED light extraction efficiency (30.56%), the efficiency raises by 63%. The research can provide theoretical research methods for the future design of LED with high light extraction efficiency, and provide theoretical guidance for the preparation of devices.