GaN基高压直流发光二极管制备及其性能分析

GaN基高压直流发光二极管工艺制备, 采用蓝宝石图形衬底(PSS) 外延片制备正梯形芯粒结构的GaN基高压直流LED.相对其他结构器件, 该结构器件发光效率最高, 封装白光后, 在色温4500 K, 驱动电流20 mA时, 光效116.06 lm/W, 对应电压50 V. 测试其I-V曲线表明, 开启电压为36 V, 对应驱动电流为1.5 mA; 在电流15 mA至50 mA时, 光功率随驱动电流增加近似于线性增加, 在此区域光效随电流增加而降低的幅度比较缓慢, 表明GaN基高压直流LED适宜于采用大电流密度驱动, 而不会出现驱动电流密度增加导致量子效率明显下降(efficiency droop), 为从芯片层面研究解决量子效率下降难题提供了一种新思路.

The preparation and performance analysis of GaN-based high-voltage DC light emitting diode

The design and the preparation of GaN-based high-voltage DC light emitting diode are realized. It is found that the device, whose chip structure is truncated pyramid using the epitaxial wafer whose subsrate is a patterned sapphire substrate, has a higher luminous efficiency than other chip structures. The luminous efficiency increases up to 116.06 lm/W when the device is packaged into white LED at a color temperature of 4500 K which is driven by 20 mA, and the corresponding voltage is 50 V. The I-V curve shows that the threshold voltage is 36 V, corresponding to a drive current of 1.5 mA. The optical power increases approximately linearly with the increase of driving current when the driving current increases from 15 mA to 50 mA, and the luminous efficiency in this range decreases more slowly with the increase of driving current, indicating that the GaN-based high-voltage DC LED is favourably driven by large current density, and severe efficiency droop will not appear as the drive current density increases, which offers a new idea for studying and solving the efficiency droop problem from the chip level.