Well-controlled wet etching of ZnO films using hydrogen peroxide solution

We propose hydrogen peroxide (H2O2) solution as a novel and promising etchant for ZnO thin film with well-controlled etching performances and enhanced ultraviolet (UV) luminescence, which is also facile, inexpensive and environmentally friendly. We have analyzed its etching mechanism and surface modification effect for ZnO. Using this etchant, fine patterns have been transferred to the ZnO single-crystal films with good fidelity. The etching performances have been comprehensively investigated using Raman spectroscopy, scanning electronic microscopy (SEM), atom force microscopy (AFM), surface profiler and photoluminescence (PL) spectrometer. The results have shown that ZnO films after the long-time etching exhibited linear etching rate, smooth profile and increased UV emission, which enables H2O2 solution as an excellent wet etchant for various ZnO-based optoelectronic devices.