Minority carrier diffusion length in GaN and ZnSe

We estimated minority carrier diffusion length and lifetime of GaN and ZnSe using the electron-beam-induced current method. The minority carrier diffusion length of both p-type and n-type GaN is about 0.9 μm, which is comparable to that of ZnSe. The threading dislocation density in GaN on sapphire, however, is several orders larger than that in ZnSe on GaAs. Therefore, a comparison with ZnSe shows that threading dislocations in GaN on sapphire do not act as efficient trap centers for minority carriers.