Persistent photoconductivity in Ga1-xInxNyAs1-y

Electrical properties of unintentionally doped p-type Ga0.95In0.05N0.013As0 .987 quaternary alloys grown by metal-organic vapor-phase epitaxy have been investigated by Hall-effect and photoconductivity measurements. Persistent photoconductivity (PPC) has been observed in this material at temperatures T < 320 K. The PPC buildup and decay kinetics have been systematically mea sured at different temperatures and photoexcitation energies and formulated in the context of lattice-relaxed deep levels (or AX-like centers). The pa rameters which characterize the AX centers in GaInNAs, namely, the thermal and optical ionization energies, hole capture barrier, and the Stokes shift , have been determined. Our results indicate that AX-like deep levels stron gly influence the electronic properties of the GaInNAs quaternary system. ( C) 1999 American Institute of Physics. [S0003-6951(99)01039-6].