【作者】 耿硕麒；

【导师】 赵修建；

【作者基本信息】 武汉理工大学 ， 材料学， 2012， 硕士

【摘要】 透明导电氧化物(TCO)薄膜因为具有在可见光区透明和电阻率低的特性,被广泛的应用在各种光电器件中,如平面液晶显示器(LCD)、太阳能电池、节能视窗、半导体器件、热电／光电材料中。二氧化锡(Sn02)薄膜由于具有对紫外吸收系数大、可见光透光率高、化学性能稳定以及室温下抗酸碱能力强等优点,成为了应用最广泛的TCO薄膜之一。目前已投入应用的TCO薄膜大多为n型电子导电,p型空穴导电的TCO薄膜一直难有突破。如果能制备电学性能与n型TCO薄膜相匹配的p型导电薄膜,不仅能拓宽TCO薄膜的应用范围,还可以制备出透明pn结,成为光电子信息元器件领域的一项重大进步。依据半导体物理理论,通过浅能级掺杂受主元素可以使氧化物薄膜实现p型导电性能。在此理论基础之上,本文总结已报道成果并改进,研究了采用磁控溅射法对不同类型的靶材进行溅射,通过掺杂浅能级元素Sb制备p型导电透明SnO2:Sb (ATO)薄膜。通过控制溅射的工艺条件和对薄膜进行退火热处理,使Sn02晶格中Sb有效替代Sn原子位置,形成受主掺杂,从而使薄膜具有p型导电性能。实验发现,采用直流反应溅射合金靶,在氧气流量小于8sccm、衬底温度在200-250℃时,能够获得具有p型导电性能的ATO薄膜；当氧流量为4sccm,衬底温度200℃时,空穴浓度最高达到4.223×1019cm-3,电导率最高达到0.3973S·cm-1。采用射频溅射法,对高纯氧化物陶瓷靶进行溅射并热处理,比直流反应溅射法更易获得结晶良好、成分均匀、结构平整的p型导电ATO薄膜,热处理温度对薄膜的导电性能至关重要。射频沉积的ATO薄膜在氩气气氛中热处理后,形成金红石结构的Sn02晶体,可见光区的平均透过率在80%以上,且均为p型导电。其中在650℃热处理4小时的ATO薄膜具有最好的p型导电性能,相较于已报道的其它p型导电薄膜,空穴载流子浓度高出1-2个数量级,达到1.722×1020cm-3,电导率达到60.61S·cm-1。通过测试发现,热处理温度能影响受主掺杂效率和薄膜的结晶结构,进而影响薄膜的p型导电性能。此外,基于具有优良性能的p型导电ATO薄膜,与导电性能相匹配的n型ZnO:Al (AZO)薄膜制备的异质透明pn结,开路电压7.40V,无反向漏电电流,具有良好的整流特性。更多还原

【Abstract】 Transparent conductive oxide (TCO) films are widely applied in various optoelectronic devices, such as solar cells, thermoelectric materials and transparent electrodes, due to the characteristics of transparency in the visible region and low resistivity. Due to the high ultraviolet absorption coefficient and visible light transmittance, resistance of alkalinity or acidity at room temperature and chemical stability, tin dioxide (SnO2) film became one of the most widely applied TCO films. At present, TCO films in application are mostly n-type conductive, p-type conductive TCO films matching with the corresponding n-type films can be prepared a transparent pn-junction, that will be a significant progress in the field of electronic components.According to the theory of semiconductor physics, the shallow level doping of the main elements can provide the p-type conductive properties of the oxide film. Base on this theory, summarize and improve the reported results,we study the preparation of p-type conductive SnO2:Sb (ATO) films using magnetron sputtering method of doping shallow level element Sb by sputtering different types of target. By controling the sputtering process conditions and annealing treatment for the deposited ATO films, make Sb take the Sn atomic positions in the SnO2lattice of effectively, forming the acceptor doping, so that make the ATO films have p-type conductivity. By DC reactive magnetron sputtering the Sn/Sb alloy-target, oxygen flow rate less than8sccm, substrate temperature200~250℃to fabricate p-type conductive ATO film; When the oxygen flow keeps at4sccm, substrate temperature at200℃, the hole-concentration of p-type ATO films reaches4.223x1019cm-3, the conductivity reachs0.3973S·cm-1. Using RF magnetron sputtering ceramic target are more likely to get good crystallization, uniform components, dense structure p-type ATO films than DC reactive magnetron sputtering, the annealing treatment temperature is very important for the conductivr properties of the films. The deposited ATO films annealed at650℃in argon atmosphere for4hours has the best p-type conductivity compared with other p-type TCO films reported before, the hole-carriers concentration is1-2orders of magnitude higher than the reported, reachs1.722x1020cm-3, the conductivity is60.61S·cm-1, the average visible transmittance is more than80%. Through the analysis, we find that annealing treatment affects acceptor doping efficiency and crystal structure of the ATO films, than influence the p-type conductive properties. Crystal good components uniform, structure, the formation of the p type conductive ATO film, heat treatment temperature on the electric properties of the film is very important.In addition, based on the the excellent performance of p-type conductive ATO film and matching n-type conductive ZnO:A1(AZO) film, we fabricate the transparent heterogeneous pn-junction. It has good rectifier characteristics, open-circuit voltage7.40V, and no reverse leakage current.更多还原