Department of Solid State Physics, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032, India.
ACS Appl Mater Interfaces. 2010 Oct;2(10):2898-903. doi: 10.1021/am1006047.
We have sputtered Zn onto quasi-one-dimensional ZnO nanowires (NWs) in order to investigate the effect of Zn diffusion on the photoluminescence and photoconduction properties of ZnO NWs. Elemental mapping clearly indicates higher Zn concentration in the NWs due to diffusion of Zn. The Zn-sputtered NWs show an enhanced ultraviolet emission with 7 nm red shift. Since the ionization energy of Zni is 51 meV, the enhanced PL emission with a red shift is correlated to the coupling between free exciton and zinc interstitials (Zni) defects. The photocurrent transients show almost 20 times more photocurrent generation in Zn/ZnO NWs compared to the as-grown NWs. In contrast, the thin film shows no significant change in the photoluminescence and photoconductivity. Based on the photoconductivity and photoluminescence results, we predict that Zn diffusion in the NWs occurs easily compared to the films because of the smaller dimensions of the NWs.
我们已经溅射了 Zn 到准一维 ZnO 纳米线（NWs）上，以研究 Zn 扩散对 ZnO NWs 的光致发光和光电导性能的影响。元素映射清楚地表明，由于 Zn 的扩散，NWs 中的 Zn 浓度更高。Zn 溅射的 NWs 显示出增强的紫外发射，红移为 7nm。由于 Zni 的电离能为 51meV，因此具有红移的增强 PL 发射与自由激子和锌间隙（Zni）缺陷之间的耦合有关。与未生长的 NWs 相比，Zn/ZnO NWs 的光电流瞬态显示出近 20 倍的光电流产生。相比之下，薄膜在光致发光和光电导性方面没有明显变化。基于光电导性和光致发光结果，我们预测由于 NWs 的较小尺寸，Zn 在 NWs 中的扩散比在薄膜中更容易发生。
