发布时间：2025-04-30

论文名称：Enhancing Light Emission of ZnO Microwire-Based Diodes by Piezo-Phototronic Effect

发表刊物：Nano Letters

摘要：Light emission from semiconductors depends not only on the efficiency of carrier injection and recombination but also
extraction efficiency. For ultraviolet emission from high band gap materials such as ZnO, nanowires have higher extraction efficiencies than thin films, but conventional approaches for creating a p
n diode result in low efficiency. We exploited the noncentral symmetric nature of n-type ZnO nanowire/p-type GaN substrate to create a piezoelectric
potential within the nanowire by applying stress. Because of the polarization of ions in a crystal that has noncentral symmetry, a piezoelectric potential (piezopotential) is created in the crystal under stress. The piezopotential acts as a “gate” voltage to tune the charge transport and enhance carrier injection, which is called the piezo-phototronic effect. We propose that band modification traps free carriers at the interface region in a channel created by the local piezoelectric charges. The emission intensity and injection current at a fixed applied voltage have been enhanced by a factor of 17 and 4, respectively, after applying a 0.093% compressive strain and improved conversion efficiency by a factor of 4.25. This huge enhanced performance is suggested arising from an effective increase in the local “biased voltage” as a result of the band modification caused by piezopotential and the trapping of holes at the interface region in a channel created by the local piezoelectric charges near the interface. Our study can be extended from ultraviolet
range to visible range for a variety of optoelectronic devices that are important for today’s safe, green, and renewable energy technology.

合写作者：Qing Yang; Wenhui Wang; Sheng Xu; *Zhong Lin Wang

卷号：11

页面范围：4012-4017

是否译文：否

发表时间：2011-08-08