The Mechanism of Charge Flow and Electric Current in Porous GaN Thin Films during Photo Electrochemical Etching

In this work nano-porous structures of n-GaN was fabricated using simple photoelectrochemical etching techniques. The electrolyte was H2SO4:H2O2 under direct current density of 5 mA/cm2 for 30 min. Scanning electron microscopy (SEM) has been used to studied the morphology, the size, and the shape of the pores of n-GaN nanostructures. The mechanism of charge and current flow in photoelectrochemical etching process was investigated deeply. The electrical and chemical behaviour of the electrolyte-GaN junction has been studied. The energy diagram of an n-GaN and the electrolyte was used to illustrate the charges flow mechanism. A simple model depend on two parallel plate capacitors was used to understand the etching mechanism at the GaN electrolyte interface. This mechanism was confirmed by J-t curve