NiO基半导体光电薄膜的制备及性能研究

【作者】 何作鹏；

【导师】 季振国；

【作者基本信息】 浙江大学 ， 材料物理与化学， 2005， 硕士

【摘要】 氧化镍是具有典型3d电子结构的氧化物,是一种P型氧化物半导体材料,Ni0被广泛应用于透明导电膜,电致变色器,气体敏感等领域。本文综合论述了NiO、MgxNi1-xO、CuxNi1-xO的制备方法以及最新相关研究的最新进展和应用前景。研究了热处理温度对NiO薄膜的结晶状态、光学性质的影响;结果表明,NiO薄膜的在一定温度下,呈现择优取向生长趋势,晶粒尺寸随着热处理温度的升高而增大;但热处理温度过高,NiO薄膜与衬底发生反应生成Ni2SiO4,反而导致晶粒尺寸减小;与此同时,NiO薄膜的光学禁带宽度随着晶粒尺寸的增大而变小。为了调节NiO薄膜的禁带宽度,使之适应不同应用的需要,我们尝试通过掺杂调节NiO薄膜的禁带宽度。通过在NiO中掺Mg形成了MgxNi1-xO固溶体,成功实现了NiO禁带宽度向高端移动。实验结果表明,当Mg含量在0. 2-0. 3之间时,MgxNi1-xO薄膜的禁带宽度处于240-280nm,正好处于目盲光谱范围。光谱响应测试表明,Mg0. 3Ni0. 7O对太阳光不敏感,而对254nm的紫外光具有很好的响应特性,电阻变化高达40%。以上结果说明MgxNi1-x是一种具有潜在应用前景的太阳盲区紫外探测器用材料。另一方面,我们通过在NiO中掺Cu,形成了CuxNi1-xO,成功使得NiO的禁带宽度向低端移动。实验结果表面,当Cu含量的在0-0. 2时,CuxNi1-xO薄膜的光谱响应范围从紫外光谱阶段向可见波段移动,同时,薄膜仍保持良好的电致变色性能。电致变色性能测试结果显示,Cu0. 2Ni0. 8O薄膜具有最好的电致变色特性,且薄膜的着色深度随Cu的含量增加而变大。 因此CuxNi1-xO是一种具有应用前景的禁带宽度可调的电致变色材料。利用在NiO中掺入Mg和Cu,可以在3. OeV-5. 0cV范围内调节NiO基薄膜的禁带宽度,有望在宽禁带异质结、量子阱器件等方面得到应用。更多还原

【Abstract】 NiO is a p-type transparent conductive oxide with typical 3d electron structure. It is widely used in many fields, such as electrodes, gas sensors, and in smart windows.In this paper, growth techniques of NiO thin films and recent research progresses and potential applicatuions were discussed, and NiO based alloy oxides AxN1-x O, i.e., NiO, MgxNi1-xO, and CuxNi1-xO films were synthesized by sol-gel dip-coating methods.MgxNi1-xO and CuxNi1-xO thin films were synthesized to tune the band-gap of NiO up and down, respectively. Results showed that the band-gap of MgxNi1-xO (0.2<x<0.3) thin films was in the range of 240-280nm, i.e., in the solar-blind region. Photo-response testing of the film with x=0.3 further proved that it was sensitive to 254nm ultraviolet light, while it showed weak response to direct sunlight, indicating potential applications of the MgxNi1-xO (0.2<x<0.3) thin films in solar-blind UV detectors.For CuxNi1-xO thin films, results showed that, compared to NiO, it has a narrower band-gap, which shifted from near UV into visible region while keeping the high transmittance and good electrochromic properties of pure NiO. Electrochromic testing results showed that the change in transmittance (AT%) increased as the content of copper increased for the light with wavelength of 610nm. For Cu0.2Ni0.8O films, the AT% was up to 70%. Our results indicating potential applications of the CuxNi1-xO (0.2<x<0.3) thin films in electrochromic devices.更多还原