Preparation Of CuO Nano-materials And Research On The Photovoltaic Properties Of CuO Thin Film

With fossil fuels and non-renewable energy sources declining and its pollution to the environment increasingly obvious, the clean, pollution-free,renewable energy sources has been increasing for the demand of the global. Nano photovoltaic devices with their unique advantages gradually become a research hot. In order to prepare low-cost, high conversion efficiency of nano photovoltaic devices, people have been exploring a new type of solar cell materials for the purpose to improve the photoelectric conversion efficiency and reduce production costs. With many new materials emerging and the continuous development of related science and technology, CuO nano structures hetero junction solar cells show unprecedented prospect and commercial value. The band gap of CuO is1.2eV-1.9eV, because it is a natural p-type semiconductor material and well matched to the solar spectrum, theoretically with high photoelectric conversion efficiency; and non toxic,non pollution;rich Cu resources, cheap;the preparation process is relatively simple, thus, CuO has broad application prospects in the field of optoelectronics. Above all, the preparation of photovoltaic nano devices based on SOI is compatible with microelectronics CMOS technology, and to achieve OEIC monolithically integrated and many other advantages, the preparation of CuO nano wires on SOI substrate has a very important practical significance. In this dissertation, the rushes-like CuO nano wires were prepared by using copper film growth method and heat treatment combination; and three morphology CuO nano structures were prepared by the electrochemical deposition and annealing combining, the field emission properties of nano wires, nano belts, nano sheet were analyzed; the characteristics of CuO nano wire hetero structures was studied, and the p-CuO/n-Si structure hetero junction solar cells were successfully prepared by using DC magnetron sputtering and utilize its photovoltaic effect, absorption spectroscopy and Ⅰ-Ⅴ characteristic curves were studied; Finally, CuO nano structures with different morphologies were prepared by using hydrothermal synthesis and do a preliminary study. The thesis conclusions and innovations are as follows:1.For the first time, the cattle-like CuO nano-wires were prepared by the copper film growth method and heat treatment on the SOI substrate. SEM results show that its diameter is about 80-100nm, its length is about10μm; the HRTEM results show that the plane spacing of nano-wires is0.23nm; XRD results show that the XRD spectra of CuO nano-wires are good consistent with the standard lines (JCPDS05-0661) of CuO nano-wires crystal structure;And the growth mechanism of needle-like Cu (OH)2precursor nano-wires were studied in detail.2.When we adjusted the electrolyte concentration, the deposition time, the reaction voltage, the annealing temperature; CuO nano-wires and nano-belts were prepared by electrochemical deposition, above all, the nano-scale film structure was successfully synthesized for the first time. The SEM results showed that the characteristic of nano-materials are large area growth, uniform size,and so on. The XRD results show that CuO nanowires are good crystalline and high purity. Secondly, the formation mechanism of Cu(OH)2precursor was researched in detail.3.Various properties of the solar cell were tested, including solar spectroscopy, hall effect measurement, the testing of Ⅰ-Ⅴ characteristics. The results show that the hetero-junction solar cell has good rectifying properties, the fill factor is23%.4.CuO nano-structures (nano-straw, nano-spheres, nano-honeycomb) with different morphologies were prepared by the hydrothermal synthesis on copper, and the formation mechanism of the products were studied in detail. SEM results show that the growth density of product was high, CuO nano-Straw is growing from the bottom to the top, leading to rough bottom and fine tip. The length of CuO nano-Straw is25-40μm, the diameter of the top is100-250nm, the diameter of the bottom is400-600nm; XRD and HRTEM results show that CuO nano-straws were high purity and good crystallinity.