Stable and Reversible Photoluminescence from GaN Nanowires in Solution Tuning by Ionic Concentration

Nanoscale Research Letters

Wei-Cheng Yu¹  Yi-Chia Chou¹  Hsiao-Wen Zan²  Ya-Wen Ho²  Anh Thi Nguyen³  Hsin-Fei Meng³ 

[1] Department of Electrophysics, National Yang Ming Chiao Tung University, 30010, Hsinchu, Taiwan;Department of Photonics, National Yang Ming Chiao Tung University, 30010, Hsinchu, Taiwan;Institute of Physics, National Yang Ming Chiao Tung University, 30010, Hsinchu, Taiwan;

关键词: GaN nanowires;    Photoluminescence response;    Ionic concentration;    Physical interaction;    Reversibility;   

DOI  :  10.1186/s11671-021-03473-7

来源: Springer

【 摘 要 】

We report response of photoluminescence (PL) from GaN nanowires without protection in solutions. The distinct response is not only toward pH but toward ionic concentration under same pH. The nanowires appear to be highly stable under aqueous solution with high ionic concentration and low pH value down to 1. We show that the PL has a reversible interaction with various types of acidic and salt solutions. The quantum states of nanowires are exposed to the external environment and have a direct physical interaction which depends on the anions of the acids. As the ionic concentration increases, the PL intensity goes up or down depending on the chemical species. The response results from a competition of change in surface band bending and charge transfer to redox level in solution. That of GaN films is reported for comparison as the effect of surface band bending can be neglected so that there are only slight variations in PL intensity for GaN films. Additionally, such physical interaction does not impact on the PL peaks in acids and salts, whereas there is a red shift on PL when the nanowires are in basic solution, say NH4OH, due to chemical etching occurred on the nanowires.

【 授权许可】

CC BY