Enhanced ultraviolet photoconductivity in porous GaN prepared by metal-assisted electroless etching

The ultraviolet photoconductivity of porous GaN (PGaN) produced by Pt-assisted electroless etching has been investigated. The photoresponse of PGaN prepared from highly doped GaN (n>1018cm−3) shows enhanced (15×) magnitude and faster decay of persistent photoconductivity relative to bulk crystalline (CGaN), suggesting advantages for PGaN in photodetector applications. A space charge model for changes in photoconductivity is used to explain these observations. Heightened defect density in the etched material plays an important role in the enhanced photoconductivity in PGaN. Flux-dependent optical quenching (OQ) behavior, linked to the presence of metastable states, is also observed in PGaN as in CGaN.