氮掺杂对SnO2薄膜光电性能的影响

SnO2薄膜具有透明导电的特性,因而被制成透明电极而广泛应用于平板显示器和太阳能电池中。研究表明,经掺杂的薄膜具有更优异的光电性能,然而传统的掺杂元素Sb,Te或F较为昂贵且有毒性,因此,掺氮将有望解决上述问题。本文利用反应射频磁控溅射法制备出不同氧含量的SnO2以及氮掺杂SnO2薄膜,并分析了薄膜的形貌结构及光电性能。结果表明:薄膜沉积过程中氧分压和氮掺杂对薄膜性能影响较大。在SnO2薄膜中,晶粒呈包状形态,随着氧分压的增加,晶粒取向从(101)转向(110)方向,晶粒尺寸逐渐变小,可见光透光率提升到80%以上,光学带隙增加到4.05 eV;在氮掺杂SnO2薄膜中,晶粒呈四棱锥形态,晶粒取向为(101)方向,随着氧分压的增加,可见光的透过率同样提升到80%以上,光学带隙增加到3.99 eV。SnO2薄膜和氮掺杂SnO2薄膜的电阻率最低分别达到1.5×10-1和4.8×10-3Ω.cm。

Influence of N-Doping on Microstructures and Properties of SnO2 Films

The nitrogen-doped SnO2 thin films were deposited by reactive RF magnetron sputtering on quartz substrates.The impacts of the deposition conditions,including the nitrogen doping,sputtering power,substrate temperature,ratios of O2/N2 and O2/Ar gas-flow rate and pressure,on the microstructures and optical and electrical properties of the N-doped SnO2 film were studied.The films were characterized with X-ray diffraction,X-ray photoelectron spectroscopy,scanning electron microscopy,and conventional surface probes.The results show that the nitrogen doping and oxygen partial pressure significantly affect the microstructures and properties of the fairly compact uniform films.For instance,the N-doped SnO2 films,grown at the optimized oxygen partial pressure and N-doping level,have a transmittance over 80% in the visible light range,a band-gap of 3.99 eV,and the lowest sheet resistance of 4.8×10-3 Ω·cm.The advantages of N-doping over doping of Sb,Te and F were also discussed.