Sathyamoorthy R, Sudhagar P, Chandramohan S, Pal U
PG and Research Department of Physics, Kongunadu Arts and Science College, Coimbatore 641029, India.
J Nanosci Nanotechnol. 2008 Dec;8(12):6481-6.
Using an integrated physical-chemical approach, nanocrystalline cadmium sulfide (CdS) thin films were prepared by evaporating chemically synthesized CdS nanorods. Both the CdS nanorods and nanocrystalline thin films exhibited hexagonal wurtzite structure. Chemically synthesized CdS nanorods of about 7 nm average diameter were flexible, frequently folded to have elliptical cage linked chain structures and aggregate to form nanorod bundles. The bandgap energy of the nanocrystalline CdS films suffered a blue shift of about 0.07 eV due to intermediate quantum confinement of charge carriers. The reaction atmosphere was found to have strong effects on the particle size control of the nanostructures. Room temperature photoluminescence (PL) spectra of the films revealed a broad emission at about 429 nm related to recombination of excitons and shallowly trapped electron-hole pairs, along with the near-band-edge emission. Influence of particle size and defects on the structural and optical properties of CdS nanorods and nanocrystalline thin films are discussed.
采用物理化学集成方法，通过蒸发化学合成的硫化镉（CdS）纳米棒制备了纳米晶硫化镉（CdS）薄膜。CdS纳米棒和纳米晶薄膜均呈现六方纤锌矿结构。化学合成的平均直径约为7nm的CdS纳米棒具有柔韧性，经常折叠形成椭圆笼状连接链结构，并聚集形成纳米棒束。由于载流子的中间量子限制，纳米晶CdS薄膜的带隙能量发生了约0.07eV的蓝移。发现反应气氛对纳米结构的粒径控制有很强的影响。薄膜的室温光致发光（PL）光谱显示，在约429nm处有一个与激子和浅俘获电子-空穴对复合相关的宽发射峰，以及近带边发射峰。讨论了粒径和缺陷对CdS纳米棒和纳米晶薄膜结构和光学性质的影响。
