The reverse-bias current-voltage and deep-level transient spectroscopy characteristics of a Ga0.90In0.10N0.033As0.967/GaAs positive-intrinsic-negative photodiode (Eg = 0.92eV) were presented, and a trap-assisted tunnelling model which considers generation-recombination and tunnelling mechanisms. Using trap parameters obtained from the deep-level transient spectroscopy measurement, the model generates current-voltage characteristics of the photodiode, which were found to be in good agreement with experimental current-voltage curves at different temperature. The model also suggested that high dark current at low reverse-bias voltage was caused by the presence of traps which have low activation energy. Furthermore, it was predicted that approximately ten times reduction in the dark current could be achieved when the trap concentration of type H-1 (Ea = 0.15eV) was reduced by one order. On the other hand, a similar reduction in defect concentration of type H-2 (Ea = 0.40eV), which was nearer to mid-gap does not produce the same effect.

Defect-Induced Trap-Assisted Tunnelling Current in GaInNAs Grown on GaAs Substrate. W.K.Loke, S.F.Yoon, S.Wicaksono, K.H.Tan, K.L.Lew: Journal of Applied Physics, 2007, 102[5], 054501