Rapid synthesis of SrTiO3 nanocubes and replacement of the high-cost platinum electrode with SrTiO3@PANI nanocomposite in dye-sensitized solar cells

Abstract

In this report, SrTiO3 was synthesized in a short time (10 min) as a perfect nano-cube shaped and high-quality crystal using microwave assisted method without any further annealing process. Moreover, SrTiO3 nanocubes were incorporated into the polyaniline (PANI) structure at different amounts and resulted nanocomposites were employed in dye sensitized solar cell (DSSC) as counter electrode (CE). Incorporation of SrTiO3 nanocubes led to enlargement of active surface area and increment in electrocatalytic activity of nanocomposites, resulting in lower electron transfer resistance and excellent charge transfer kinetics at the interfaces of CE/FTO and CE/electrolyte. As a result, photovoltaic (PV) parameters of DSSC improved with incorporation of SrTiO3 nanocubes compared to the bare PANI. Furthermore, 2 wt % SrTiO3 doped PANI nanocomposite (SP2) CE exhibited a better catalytic performance in comparison to the bare PANI and Pt CEs, resulting in higher power conversion efficiency (PCE). The PCE of the DSSC with SP2 CE was extracted as 7.57 %, while the PCEs of the cells employing bare PANI and conventional Pt CEs were calculated as 5.46 % and 7.16 %, respectively. By incorporation of SrTiO3 nanocubes, the PCE of DSSC with bare PANI is enhanced as 38.7 % due to the high redox nature of SrTiO3 and expanding of active surface area stem from nanocubes of SrTiO3. The obtained results suggest that SrTiO3 can be synthesised using simple microwave assisted method in a very short time and with high quality without any further annealing procedure. Furthermore, doping of 2 wt % SrTiO3 nanocubes into PANI can be alternative to the high-cost and rare Pt for commercialization of the DSSCs in near future.