Tandem architectures using organic/inorganic hybrid semiconductors are a promising strategy to overcome the Shockley-Queisser limit of single-junction (SJ) solar cells as already demonstrated in III-V compound semiconductors. Here, we present a highly-efficient dye-sensitized solar cell (DSSC)/silicon (Si) monolithic tandem cell by utilizing PEDOT:FTS as an interfacial catalytic layer, which has higher transparency and lower charge-transfer resistance compared to conventional Pt. In addition, the amount of dye adsorbed on the surface of TiO2 nanoparticles is fine-tuned for precise current matching between the two sub-cells. Based on these rational approaches, the DSSC/Si tandem cell exhibited a much higher power-conversion efficiency (PCE) of 17.2% compared to the stand-alone SJ devices of DSSCs (-11.4%) or Si (-12.3%) cells. The PCE of the best tandem cell is 18.1%. To the best of our knowledge, our tandem cell has a record-high PCE among all tandem cells involving DSSCs and also the highest improvement of PCE among all tandem cells based on dissimilar photovoltaic materials. The 2-terminal DSSC/Si tandem solar cells exhibit a high Voc value of 1.36 V. The DSSC/Si tandem solar cells are externally connected to a Pt electro-catalyst for use as water splitting cells. Solar-to-hydrogen conversion was accomplished at 0.65 V vs. Pt bias. We expect that a tandem architecture based on organic-inorganic hybrid materials can provide a promising way to realize low-cost and high-efficiency photovoltaic devices for solar cells and hydrogen generation.
Bibliographical noteFunding Information:
This research was financially supported by the KIST-UNIST partnership program (1.150091.01/2.150464.01) and by the Mid-career Researcher Program through the National Research Foundation of Korea (NRF) grant funded by the Korea government (NRF-2014R1A2A1A11052455). J. H. Park acknowledges support from the National Research Foundation of Korea (NRF) grant funded by the Korea government (NRF-2013R1A2A1A09014038), (NRF-2015M1A2A2074663).
© The Royal Society of Chemistry 2016.
All Science Journal Classification (ASJC) codes
- Environmental Chemistry
- Renewable Energy, Sustainability and the Environment
- Nuclear Energy and Engineering