掺Sn的In_2O_3透明导电膜生长优先取向对其光电性能的影响

Effect of Growth-Preferred Orientation on the Photoelectric Properties of ITO Thin Film

采用反应热蒸发法制备掺Sn的In2O3(ITO)透明导电膜,系统研究了ITO薄膜生长的优先取向对其光电性能的影响.结果表明,ITO薄膜(400)取向的优先生长对其透过率影响很小,但可明显增加载流子迁移率,从而有效降低了薄膜的方块电阻.在两个相同的薄膜硅/单晶硅太阳能电池上分别沉积(222)和(400)ITO优先取向膜,光电转换效率分别为10.3%和12.9%,表明(400)取向更有利于提高电池效率.经优化,最佳衬底温度(Ts)为225℃,最佳氧流量(fO2)为4sccm.在优化的沉积条件下制备ITO薄膜,其电阻率可达到4.8×10-4Ω.cm,可见波段的透过率大于90%,性能指数为3.8×10-2□/Ω.

Tin-doped indium oxide （ITO） thin films were deposited on glass substrates by reactive thermal evaporation. The effect of the preferred orientation of ITO thin film on its performance has been studied. The results show that the grain ori-entation in the （400） direction does not influence the transmissivity and the carrier concentration,but enhances the carrier mobility. The transmissivity of ITO films is over 90% in the visible wavelength region （except for film deposited at 125℃）. To deposit （222）- and （400）-oriented ITO films on the same thin film Si/single crystalline Si solar cells separately, the photo-electric conversion efficiency is 10.31% and 12.92% ,respectively. This result indicates that the （400） preferred orientation of ITO film can improve the efficiency of solar cells. The optimal substrate temperature and oxygen flow are 225℃ and 4sccm,respectively. Under this condition, the resistivity of ITO film is 4.8 × 10^-4Ω.cm, and the figure of merit reaches 3.8×10^-2□/Ω.