On the invitation by Editor-in-Chief of Accounts of Chemical Research, Prof. Cynthia J. Burrows, Prof. Zhong-Sheng Wang recently published the latest advances in Accounts of Chemical Research titled as “Metal Selenides as Efficient Counter Electrodes for Dye-Sensitized Solar Cells” (Acc. Chem. Res. 2017, DOI: 10.1021/acs.accounts.6b00625). This Account introduces the progress in metal selenides applied as counter electrodes in dye-sensitized solar cells (DSSCs), as shown in Figure 1, and points out current challenges and future development direction of metal selenide CE materials.

Figure 1. Schematic figure for metal selenides with various morphologies and stoichiometric ratios for use as counter electrodes in dye-sensitized solar cells

To lower the cost caused by the typically used Pt CE in DSSCs, which restricts the large-scale application due to its low reserves and high price, they developed a facial one-step low temperature hydrithemal approach for in-situ growth of metal selenides (Co0.85Se and Ni0.85Se) on conductive substrates. The as-prepared metal selenides films can be used directly as transparent counter electrodes for DSSCs without any post-treatments achieving high photovoltaic performance. In particular, graphene-like Co0.85Se nanosheet exhibits higher electrocatalytic activity than Pt for the reduction of triiodide and hence higher power conversion efficiency (9.40%) than that (8.64%) with Pt (J. Am. Chem. Soc., 2012, 134, 10953-10958.). This finding has inspired extensive studies on developing new metal selenides in order to seek more efficient CE materials for low-cost DSSCs in the past years.

We appreciate the financial supports from the National Natural Science Foundation of China (Grant: 21673049) and the personalized support from Fudan University for original research.

Original link: http://pubs.acs.org/doi/pdf/10.1021/acs.accounts.6b00625