Fabrication and optical properties of lift-off InP membranes

An electrochemical etching based on HCl solution was developed for use in the chemical lift-off of InP membranes. Under the same etching conditions, the diameter of InP pores increases with the increase of etching depth or etching voltage. When the etching depth or etching voltage exceeds a critical value, the InP layer can be electropolished, leading to the lift-off of nanoporous InP membranes. The lift-off membranes can be transferred onto a substrate. Compared to the planar InP wafer, the etched InP wafer and transferred InP membrane present stronger photoluminescence emission and weaker reflectance in the range of 250-850 nm.