Shockley–Read–Hall lifetime in homoepitaxial p-GaN extracted from recombination current in GaN p–n+ junction diodes

The Shockley–Read-Hall (SRH) lifetime in homoepitaxial p-GaN (N a = 1 × 1017 cm−3) is investigated by analyzing forward current–voltage (I–V) characteristics in GaN-on-GaN p–n+ junctiondiodes with mesa-isolation structure. The ideality factor around 2 due to recombinationcurrent was obtained in the 1.8–2.7 V window, which is different from the characteristic of a p+- n− junctioninvolving considerable diffusion current. The recombinationcurrent was proportional to the junction area, indicating that the recombinationcurrent is a bulk component, not a mesa-surface component. Analyzing the recombinationcurrent with consideration of the SRH recombinationrate in the depletion layer, we obtained an SRH lifetime of 46 ps at 298 K. The temperature dependence of the I–V characteristics was also investigated and the SRH lifetimes were extracted in the range of 223–573 K. The SRH lifetime in homoepitaxial p-GaN followed the empirical power law of = 1.2 × 10−16 × T 2.25 (s).