Optoelectronic properties of gallium nitride thin membranes

Abstract

We present the results of a systematic study of persistent photoconductivity (PPC) generated by UV-excitation in thin membranes based on crystalline GaN. The PPC was found to be optically quenched under extrinsic excitation (quanta energy lower than Eg). Interesting optoelectronic phenomena have been evidenced in nanoperforated GaN membranes. In particular, nanoperforation-induced optical quenching of PPC was found to occur at temperatures T < 100 K under intense intrinsic excitation. The obtained results are discussed taking into account strong surface localization of charge carriers in GaN thin membranes as well as UV-induced reactions occurring at surface states under intense intrinsic excitation.