GaN基蓝光micro-LED的结温和载流子温度研究

Investigation of the Junction Temperature and Carrier Temperature of GaN-Based Blue Micro-LED

摘要:

结温及载流子温度因作为影响LED发光效率的重要参数而广受关注。文章研究了GaN基蓝光集成传感微小尺寸发光二极管(micro-LED)的光致发光(PL)光谱、载流子温度等随结温的变化规律。通过内置集成传感单元芯片,设计实现了GaN基蓝光micro-LED在0.04~53.4A/cm²电流密度下结温和PL光谱的实时精确测量,并将正向电压法测量结温的低温端范围拓展至123K。结果表明,低温下由于载流子泄漏、串联电阻的原因,结温与正向电压的线性斜率发生变化。针对PL光谱使用高能侧斜率法计算得到不同电流密度下的载流子温度,发现载流子温度与结温在所研究的结温和电流密度范围内可以近似用二次方程拟合,并对载流子温度随结温和电流密度变化的规律进行了分析和解释。

Abstract:

Junction temperature and carrier temperature are widely concerned as significant parameters affecting LED luminous efficiency. The variation rules of electroluminescence (EL) spectrum and carrier temperature with junction temperature of GaN-based blue micro-LED were investigated in this paper. The accurate real-time measurement of junction temperature and EL spectrum of GaN-based blue micro-LED at current densities of 0.04~53.4A/cm² were conducted by using the chip design with a built-in integrated sensor unit, and the range of the low-temperature end of the junction temperature measurement was extended to 123K using the forward voltage method. The results show that the linear slope of junction temperature and forward voltage change due to carrier leakage and series resistance at low temperature. The high-energy slope method was used for EL spectrum to calculate the carrier temperature at different current densities. It is found that the carrier temperature and junction temperature can be approximately fitted by a quadratic equation within the range of junction temperature and current density under study. And the law of the variation of the carrier temperature with junction temperature and current density was analyzed and explained.