ZnO纳米线膜的可控生长及其量子限域效应研究

针对ZnO半导体低维纳电子/光电子器件中纳米线膜的可控性差及其所导致的特性不稳定问题,利用ZnO纳米籽晶层作为引导层,以实现ZnO纳米线膜的垂直取向生长和尺度分布可控制备,并研究低维量子限域效应对ZnO纳米线膜光电特性的影响机制,利用湿化学法在氧化铟锡导电玻璃上制备ZnO籽晶层,随后利用低温水热法进行ZnO纳米线膜的引导生长,样品的显微结构和物相分析表明,通过调节籽晶热处理温度和生长液浓度能够实现ZnO纳米线直径在10～100nm内可调,籽晶热处理温度对纳米线尺度分布影响尤其显著.室温光致发光(PL)谱测试及分析表明,直径小于20nm的ZnO纳米线薄膜样品的PL谱的近紫外带边发射峰相比于更大直径的纳米线样品发生了明显的蓝移,而且半高宽显著减小.利用量子限域效应理论对PL谱带边发射峰随纳米线的尺度分布发生变化的规律进行了合理分析.

Study on Controllable Growth and Quantum Confined Effect of ZnO Nanowire Membranes

To deal with the problem that ZnO nanowire films show poor controllability and reproduction quality when they are used in nano-electronic and nano-photoelectronic devices, ZnO seeds are used as guide layers to achieve vertical oriented growth and controllable diameter distribution preparation. The influence of the low dimensional quantum confined effects to photoelec-tronic properties is studied. ZnO seed layer is fabricated by the wet chemistry method, and then ZnO nanowire membrane is generated on indium tin oxide glass substrate with low temperature hydrothermal process. It is found from the scanning electron microscope (SEM) analysis and X-ray diffraction spectra that diameters of ZnO nanowires can be tuned within the range of 10 to 100 nm by adjusting annealing temperature of ZnO seeds and concentration of growth solution, and that the size distribution of the ZnO nanowires is affected by the annealing temperature for ZnO seeds tremendously. It is also found from the measured photoluminescence (PL) spectra at room temperature that the band-edge emission peaks of samples with nanowires' diameter less than 20 nm exhibit considerable blue shift and reduction of peak width at half height compared with other samples. Quantum confined effects theory is used to explain the relativity between the diameter distribution of nanowires and their PL spectra properties.