Wide bandgap Zn2GeO4 nanowires as photoanode for quantum dot sensitized solar cells

Zn2GeO4 nanowires were directly synthesized on fluorine-doped-tin-oxide substrates and were utilized as the photoanode in quantum dot sensitized solar cells (QDSSCs). CdSe QDs were deposited on Zn2GeO4 nanowires using successive ion layer adsorption and reaction (SILAR), and absorption measurement was performed to inspect their bandgaps and corresponding band alignment with the Zn2GeO4 nanowires. The performance of the QDSSCs was characterized, and a relatively high VOC of 0.64 V was observed. Transient photocurrent and photovoltage decay measurements were also conducted to study carrier transport and recombination processes in the cells, and the obtained transport and recombination time constants and charge collection efficiency exhibited dependence on the number of SILAR coating cycles.