Kinetics of persistent photoconductivity in crystalline III–V semiconductors

Abstract

Although persistent photocurrent (PPC) in photoconductive III–V semiconductors is known to be dominated by dispersive reaction kinetics, which produce a stretched exponential function decay, exp[−(t/τ)^β], where τ is the effective reaction time and β (<1.0) is the dispersion parameter, the reason for the occurrence of the PPC is still not clear. Here, we discuss the origin of dispersive kinetic relaxation associated with a DX-like centre, i.e. deep levels associated with donors in III–V semiconductors. It is suggested that lattice relaxation of DX-like centres, accompanied by multi-phonon processes, may play a role in the dispersive nature of the PPC.

Keywords:

• Persistent photocurrent
• dispersive recombination kinetics
• DX centre
• crystalline III–V semiconductors
• GaN

Acknowledgements

R. J. F would like to thank Prof. S. Nonomura for discussions and acknowledge the Chubu Foundation and NEDO Project for their financial support of his stay in Gifu University. R. J. F and K. S. wish to acknowledge the Japan International Cooperation Agency (JICA-CADEFEST 2) for financial support to the National University of Timor Lorosa’e.