Department of Physics, University of Allahabad, Allahabad 211002, India.
Spectrochim Acta A Mol Biomol Spectrosc. 2011 Sep;79(5):1605-12. doi: 10.1016/j.saa.2011.05.019. Epub 2011 Jun 22.
Photoconductivity and photoluminescence studies of ZnO nanoparticles (NPs) synthesized by co-precipitation method capped with thioglycerol are carried out. The effect of annealing at 300°C is also studied. The transmission electron micrograph (TEM) and X-ray diffraction (XRD) pattern confirm the hexagonal wurtzite structure of ZnO nanoparticles. The UV-vis absorption spectrum of ZnO NPs shows blue shift of absorption peak as compared to bulk ZnO. The photoluminescence (PL) spectra of as-synthesized ZnO NPs show band edge emission as well as blue-green emission. After annealing band edge emission is quenched. Photocurrent is found to vary super linearly at high voltage for both as-synthesized as well as annealed ZnO NPs. Time resolved rise and decay photocurrent spectra are found to exhibit anomalous photoconductivity for as-synthesized as well as annealed ZnO NPs wherein the photocurrent decreases even during steady illumination.
采用共沉淀法合成了巯基甘油包覆的 ZnO 纳米粒子（NPs），并对其光电导和光致发光性能进行了研究。还研究了在 300°C 下退火的影响。透射电子显微镜（TEM）和 X 射线衍射（XRD）图谱证实了 ZnO 纳米粒子的六方纤锌矿结构。与体相 ZnO 相比，ZnO NPs 的紫外-可见吸收光谱显示出吸收峰的蓝移。合成的 ZnO NPs 的光致发光（PL）光谱显示带边发射和蓝绿光发射。退火后，带边发射被猝灭。对于合成的以及退火的 ZnO NPs，在高电压下，光电流发现呈超线性变化。时间分辨上升和衰减光电流谱表明，合成的以及退火的 ZnO NPs 表现出反常光电导，其中即使在稳定光照下，光电流也会下降。
