GaN基和GaAs基半导体激光器的电学特性研究

Investigation on Electrical Properties of GaN and GaAs Based Semiconductor Laser Diodes

摘要:

介绍了一种能够全面表征半导体二极管器件的电学特性的方法,此方法结合半导体二极管的正向交流特性和直流特性，称之为正向交流小信号法。利用该方法深入地研究和对比分析了GaN基和GaAs基半导体激光器的电学特性，包括表观电容、串联电阻和理想因子。实验结果表明，对于GaN基和GaAs基半导体激光器，其开始发光的过程同步于其电容由正转变为负的过程。进一步实验结果表明，GaN基半导体激光器比GaAs基半导体激光器具有更大的串联电阻和更大的理想因子。这是由于GaN基激光器的器件工艺不够完善以及外延生长的GaN材料具有很大的位错密度。该研究为提高和改善GaN基激光器的性能提供了必要的依据以及理论指导。

Abstract:

A novel method was introduced to accurately characterize the electrical properties of semiconductor diodes. The method combining the forward alternative current characteristics and direct current characteristics of the semiconductor diodes is called AC I-V method. Then the electrical properties of GaN and GaAs based semiconductor laser diodes were studied, such as the diode capacitance, series resistance and ideality factor. It is found that the capacitance becomes negative when the semiconductor diodes start to emit. Both the series resistance and the ideality factor of the GaN based semiconductor laser diodes are larger than those of the GaAs based diodes. It can be attributed to the imperfect technologies of GaN lasers and a large amount of dislocations in the GaN material.