Bi-functional lithium doping in dye-sensitized solar cells

• A TiO2/LixNi1−xO hybrid electrode was applied to a DSSC.
• Compared with a conventional DSSC, the proposed device increased Voc by 6.8% and Jsc by 24.7%.
• Li-doped NiO enhances light absorption and reduces the electrical resistivity of the electrode.

Despite intensive research into dye sensitized solar cells (DSSCs), simultaneously increasing both the short-circuit photocurrent density (Jsc) as well as open-circuit photovoltage (Voc) of cells has thus far proven impossible. This paper reports the fabrication of Li-doped NiO electrodes to investigate a bi-functional mechanism in which Li enhances light absorption, suspends electron–hole recombination, and reduces the electrical resistivity of the electrode. We also outline the optimization of sol–gel synthesis and investigate the performance of the developed DSSCs. Our results reveal a 6.8% increase in Voc as well as a 24.7% increase in Jsc, compared with a DSSC with TiO2 electrode. The proposed mechanism, based on state-of-the-art electronic structure theory, provides a valuable guide for the further development of solar cells and electrochemical devices in general.