H/Al共掺杂对ZnO基透明导电薄膜光电性质和晶体结构的影响

利用H在ZnO中作为浅施主杂质的特性，研究了H掺杂对ZnO：Al透明导电薄膜特性的影响。通过降低ZnO：Al中Al的含量并同时引入H掺杂，解决了透明导电薄膜中高导电性与高透过率之间的矛盾。H的掺杂可以显著降低ZnO基透明导电薄膜的电阻率，这是由于H一方面作为施主可以提供电子从而提高了自由载流子浓度；另一方面与ZnO晶界中的O^-结合降低了晶界势垒，提高了载流子迁移率。利用H掺杂，可以在Al掺杂量降低10倍的情况下，仍然能获得低电阻率（6.3×10^-4 Ω·cm）的透明导电薄膜，同时其近红外波段（1 200 nm）透光率从64%提高到90%。这种具有高导电性和高透光性的透明导电薄膜可以应用于各类薄膜太阳能电池中以提升器件效率。

Influence of H/Al Co-doping on Eletrical and Optical Properties and Crystal Structure of ZnO-based Transparent Conducting Films

By incorporating suitable amount of H dopants and lowering the Al contents, the conflicts between low resistivity and high transmission in transparent conducting films have been successfully solved. The reduced resistivity of ZnO:Al films by hydrogen doping is attributed to the increased carrier density and carrier mobility. Hydrogen behaves as a shallow donor in ZnO and can provide plenty of electrons. Most importantly, it can increase the carrier mobility effectively by lowering the potential barrier between ZnO grains due to the passivation of O^- defects around grain boundaries. The carrier mobility can also be increased due to the less impurity scattering induced by the lowering of Al dopants in ZnO films. With hydrogen doping, low resistivity (6.3×10^-4 Ω·cm) ZnO:Al samples with only 1/10 of Al contents compared to conventional AZO films can be got. The optical transmittance in near infrared region(1 200 nm) increases from 64% to 90% by comparing samples without and with H-doping is shown. This kind of high conductivity and high transmittance ZnO thin film will be excellent transparent conducting oxide candidate for various types of thin-film solar cells to improve the efficiency of the device.