Effects of Ga doping and hollow structure on the band-structures and photovoltaic properties of SnO2 photoanode dye-sensitized solar cells

摘要

The photon-to-electricity conversion properties of the prepared photoanode based on SnO2 nanocrystals, which are assembled as the rough hollow microspheres (RHMs), are improved by aliovalent Ga3+ doping. The conduction band (CB) of the doped SnO2 shifts negatively with increasing the Ga content from 1 to 5 mol% gradually. Moreover, the prepared Ga-doped SnO2 photoanode shows an advantage in repressing the charge recombination. As a result, both the negative shift of the CB and repressed charge recombination enhance the open-circuit photovoltage (Voc) and the short-circuit photocurrent (Jsc) of the DSSCs, and the power conversion efficiency (η) is increased by 80% at 3 mol% Ga-doping SnO2 to compare with the undoped SnO2 for DSSCs (AM 1.5, 100 mW cm-2). After treating the samples with TiCl4, an overall photoconversion efficiency (approximately 7.11%) for SnO2 based DSSCs is achieved.