Long-Term Thermal Stability of Liquid Dye Solar Cells

作者：Kontos Athanassios G^*; Stergiopoulos Thomas; Likodimos Vlassis; Milliken Damion; Desilvesto Hans; Tulloch Gavin; Falaras Polycarpos

来源：Journal of Physical Chemistry C, 2013, 117(17): 8636-8646.

DOI：10.1021/jp400060d

Laboratory-size dye solar Cells (DSCs), based on industrially feasible materials and processes employing liquid electrolytes, have been developed. Cells, based on two electrolyte solvents with different physical properties were subjected to thermal stress test at 80 degrees C for 2000 h in the dark to monitor their long-term thermal stability. The DSCs incorporating a methoxypropionitrile (MPN)-based electrolyte presented a severe efficiency loss at 1 sun AM 1.5G, of more 1 than 70% upon thermal aging, while the solar cells using tetraglyine (TG) as a high boiling point solvent attained a promising stability with only 20% loss of performance. To better understand the above behavior, systematic experiments, including optical microscopy, linear sweep voltammetry, UV-vis absorption, electrochemical impedance, and Raman spectroscopies were conducted. Virtually no dye degradation/desorption, electrolyte decomposition, semiconductor passivation, or loss of cathode activity could be identified. For the MPN-based cells, a sharp decrease in the short-circuit photocurrent was observed at high illumination intensities following thermal stress, attributed to charge transfer limitations due to severe triiodide loss, verified by different experimental techniques. These degradation effects were efficiently mitigated by replacing MPN with the high-boiling-point solvent in the electrolyte.

• 出版日期2013-5-2