【摘要】 对不同温度(120~363 K)下InGaN/GaN多量子阱(MQW)结构蓝光发光二极管(LED)的电学特性进行了测试与深入的研究。发现对数坐标下I-V特性曲线斜率随温度变化不大。分别用载流子扩散-复合模型和隧道复合模型对其进行计算,发现室温下其理想因子远大于2,并且随着温度的下降而升高;而隧穿能量参数随温度变化不大。这说明传统的扩散-复合载流子输运模型不再适用于InGaN/GaN MQW蓝光LED。分析指出由于晶格失配以及生长工艺的制约,外延层中具有较高的缺陷密度和界面能级密度,导致其主要输运机制为载流子的隧穿。更多还原

【Abstract】 The electrical characteristics of InGaN/GaN multiple quantum well(MQW) light-emitting diodes(LEDs) are investigated at different temperatures.The slope of the I-V characteristics in a semilogarithmic scale almost doesn’t depend on the temperature.According to the diffusion-recombination model and the tunneling-recombination model,the ideality factor is greater than 2.0 at room temperature,and increases with the decrease of the temperature,while the tunneling energy parameter almost dosen’t change.This indicates that the carrier main transport mechanism of InGaN/GaN MQW LEDs is not the diffusion-recombination model.It appears that the tunneling behavior dominates throughout all injection regimes in the device because of high density of defects caused by the lattice mismatch and the restriction of epitaxial growth.更多还原