紫外光照处理对TiO2膜光伏性能的影响

近年来人们利用纳米晶TiO2电极取代普通的TiO2电极[1],使其太阳能电池的光电转换效率得到很大提高.纳米晶TiO2电极具有大量表面态,在化学上表现为Ti3+或Ti—OH,对于光生电荷的分离过程和迁移过程有重要影响.这些表面化学结构的变化可能会导致TiO2的光伏性能的变化.1997年Fujishima等[2]用紫外光照射TiO2膜使它具有超亲水的性质,结构分析表明,超亲水的原因在于光照使TiO2膜的表面形成Ti—OH[3].因此,在光照处理的同时可能会导致TiO2的光伏性的变化.本文对紫外光照处理TiO2膜的光伏性能进行了研究,并结合光诱导TiO2的亲水性变化对光伏性能变化的原因进行了讨论.

Effect of UV Illumination Treatment on Surface Photovoltaic Properties of TiO2 Films

Ti O2 films and N- doped Ti O2 films were prepared by magnetron sputtering methodology.The films were illuminated at365 nm for5— 20 min followed by the measurementof contactangles and surface photovoltage spectroscopy.The results show thatfor n- type Ti O2 film,UV illumination treatment can in- crease the photovoltage,while for p- type Ti O2 film,such treatment can decreases the photovoltage.The photovoltaic changing was explained by Ti— OH group increasing due to photo- induced hydrophility.For n- type Ti O2 film,Ti— OH groups can increase the photo- induced charge separation and thus iucrease the photovoltage;for p- type Ti O2 film,Ti—OH groups decrease the photo- induced charge separation and thus decrease the photovoltage.