Ou Sin-Liang, Yu Fei-Peng, Wuu Dong-Sing
Department of Materials Science and Engineering, Da-Yeh University, Changhua, 51591, Taiwan, R.O.C.
Department of Materials Science and Engineering, National Chung Hsing University, Taichung, 40227, Taiwan, R.O.C.
Sci Rep. 2017 Oct 27;7(1):14251. doi: 10.1038/s41598-017-14592-6.
A novel fabrication method for single crystalline ZnO nanorods by pulsed laser deposition (PLD) using a chemical-bath-deposited ZnS seed layer is proposed. For the substrate temperature (T) lower than 700 °C, the PLD-ZnO showed a polycrystalline phase and film-type morphology, resulting from the ZnS seed layer with a cubic phase. However, the ZnS film became a sacrifical layer and single crystalline ZnO(002) nanorods can be achieved at T of 900 °C, where ZnS was decomposed to zinc metals and sulfur fumes. The transformation from ZnO film to nanorod microstructure was demonstrated with the change of ZnS layer into Zn grains. Enhanced performance of the metal-semiconductor-metal photodetectors were fabricated with ZnO/ZnS samples grown at T of 500, 700, and 900 °C. The responsivities (@1 V and 370 nm) of these three devices were 1.71, 6.35, and 98.67 A/W, while their UV-to-visible discrimination ratios were 7.2, 16.5, and 439.1, respectively. Obviously, a higher light-capturing efficiency was obtained in the 900 °C-grown ZnO/ZnS device owing to its one-dimensional nanostructure with high crystal quality. The results indicate PLD combined with a sacrifical nanostructure is a promising method for obtaining high-quality ZnO nanorods, which paves the way for the fabrication of high performance ZnO-based devices.
提出了一种通过脉冲激光沉积（PLD）使用化学浴沉积的ZnS籽晶层制备单晶ZnO纳米棒的新方法。对于低于700°C的衬底温度（T），PLD-ZnO呈现多晶相和薄膜型形态，这是由具有立方相的ZnS籽晶层导致的。然而，ZnS薄膜成为牺牲层，在900°C的T下可以实现单晶ZnO(002)纳米棒，此时ZnS分解为锌金属和硫烟。随着ZnS层转变为Zn晶粒，证明了从ZnO薄膜到纳米棒微观结构的转变。用在500、700和900°C的T下生长的ZnO/ZnS样品制备了性能增强的金属-半导体-金属光电探测器。这三个器件的响应度（@1 V和370 nm）分别为1.71、6.35和98.67 A/W，而它们的紫外-可见辨别率分别为7.2、16.5和439.1。显然，由于其具有高质量晶体的一维纳米结构，在900°C生长的ZnO/ZnS器件中获得了更高的光捕获效率。结果表明，PLD与牺牲纳米结构相结合是获得高质量ZnO纳米棒的一种有前途的方法，这为高性能ZnO基器件的制造铺平了道路。
