Global GET-Future Laboratory and Department of Advanced Materials Chemistry, Korea University, 2511 Sejong-ro, Sejong 339-700, Korea.
ACS Nano. 2013 Jun 25;7(6):5243-50. doi: 10.1021/nn4009774. Epub 2013 May 15.
Highly efficient counter electrodes (CEs) for dye-sensitized solar cells (DSSCs) were developed using thin films of scalable and high-quality, nitrogen-doped graphene nanoplatelets (NGnP), which was synthesized by a simple two-step reaction sequence. The resultant NGnP was deposited on fluorine-doped SnO2 (FTO)/glass substrates by using electrospray (e-spray) coating, and their electrocatalytic activities were systematically evaluated for Co(bpy)3(3+/2+) redox couple in DSSCs with an organic sensitizer. The e-sprayed NGnP thin films exhibited outstanding performances as CEs for DSSCs. The optimized NGnP electrode showed better electrochemical stability under prolonged cycling potential, and its Rct at the interface of the CE/electrolyte decreased down to 1.73 Ω cm(2), a value much lower than that of the Pt electrode (3.15 Ω cm(2)). The DSSC with the optimized NGnP-CE had a higher fill factor (FF, 74.2%) and a cell efficiency (9.05%), whereas those of the DSSC using Pt-CE were only 70.6% and 8.43%, respectively. To the best of our knowledge, the extraordinarily better current-voltage characteristics of the DSSC-NGnP outperforming the DSSC-Pt for the Co(bpy)3(3+/2+) redox couple (in paticular, FF and short circuit current, Jsc) is highlighted for the first time.
高效的染料敏化太阳能电池（DSSC）对电极（CE）使用可扩展且高质量的氮掺杂石墨烯纳米片（NGnP）薄膜开发，该薄膜通过简单的两步反应序列合成。所得的 NGnP 通过电喷雾（e-spray）涂层沉积在掺氟氧化锡（FTO）/玻璃基板上，并通过使用有机敏化剂在 DSSC 中对 Co（bpy）3（3+/2+）氧化还原对评估其电催化活性。电喷雾 NGnP 薄膜在作为 DSSC 的 CE 时表现出出色的性能。优化后的 NGnP 电极在延长的循环电势下表现出更好的电化学稳定性，其 CE/电解质界面处的 Rct 降低至 1.73 Ω cm（2），远低于 Pt 电极（3.15 Ω cm（2））的值。具有优化的 NGnP-CE 的 DSSC 具有更高的填充因子（FF，74.2%）和电池效率（9.05%），而使用 Pt-CE 的 DSSC 的 FF 和短路电流（Jsc）分别仅为 70.6%和 8.43%。据我们所知，首次突出了 DSSC-NGnP 的 Co（bpy）3（3+/2+）氧化还原对（特别是 FF 和短路电流，Jsc）的电流-电压特性明显优于 DSSC-Pt。
