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

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.