Mechanism Study of Photoluminescence Peak Shift of Transparent (In,Ga)N Nanowire Films Detached by Acid Solution

Abstract In this work, the acid solution has been demonstrated in detaching transparent (In,Ga)N nanowire films. The lift-off (In,Ga)N nanowire film remains stable after the electrochemical etching. Without obvious damages, the etching time of acid solution is possible to be longer than that of alkaline solution, which is beneficial to maintain the stability of etching. In addition, the photoluminescence (PL) peak shifts exist between the samples before and after etching. By the numerical simulations and optical experiments, it is proposed that both etching process and incident angle of the lighting source mainly contribute to the shift. When the nanowires are immersed in an acid solution, the top and edge of nanowires with low components of indium (In) are partially dissolved, leading to the increase of the overall In component. Meanwhile, different incident angles lead to the heterogeneous absorption of light by different In components within (In,Ga)N section, which should be another reason for the shift of peak position. This study is beneficial for promoting the lift-off method in the applications of transparent nanowire films.