Institute for Clean Energy & Advanced Materials, Southwest University, Chongqing 400715, P.R. China.
Phys Chem Chem Phys. 2013 Oct 14;15(38):15905-11. doi: 10.1039/c3cp52460d. Epub 2013 Aug 14.
Cu2O-ZnO nanowire solar cells have the advantages of light weight and high stability while possessing a large active material interface for potentially high power conversion efficiencies. In particular, electrochemically fabricated devices have attracted increasing attention due to their low-cost and simple fabrication process. However, most of them are "partially" electrochemically fabricated by vacuum deposition onto a preexisting ZnO layer. There are a few examples made via all-electrochemical deposition, but the power conversion efficiency (PCE) is too low (0.13%) for practical applications. Herein we use an all-electrochemical approach to directly deposit ZnO NWs onto FTO followed by electrochemical doping with Ga to produce a heterojunction solar cell. The Ga doping greatly improves light utilization while significantly suppressing charge recombination. A 2.5% molar ratio of Ga to ZnO delivers the best performance with a short circuit current density (Jsc) of 3.24 mA cm(-2) and a PCE of 0.25%, which is significantly higher than in the absence of Ga doping. Moreover, the use of electrochemically deposited ZnO powder-buffered Cu2O from a mixed Cu(2+)-ZnO powder solution and oxygen plasma treatment could reduce the density of defect sites in the heterojunction interface to further increase Jsc and PCE to 4.86 mA cm(-2) and 0.34%, respectively, resulting in the highest power conversion efficiency among all-electrochemically fabricated Cu2O-ZnO NW solar cells. This approach offers great potential for a low-cost solution-based process to mass-manufacture high-performance Cu2O-ZnO NW solar cells.
Cu2O-ZnO 纳米线太阳能电池具有重量轻和高稳定性的优点，同时具有大的活性材料界面，有潜力实现高的功率转换效率。特别是，电化学制造的器件由于其低成本和简单的制造工艺而受到越来越多的关注。然而，大多数器件是通过真空沉积到预先存在的 ZnO 层上来“部分”电化学制造的。也有一些通过全电化学沉积制成的例子，但功率转换效率（PCE）太低（0.13%）而无法实际应用。在这里，我们使用全电化学方法将 ZnO NW 直接沉积到 FTO 上，然后通过电化学掺杂 Ga 来制备异质结太阳能电池。Ga 掺杂极大地提高了光的利用效率，同时显著抑制了电荷复合。Ga 与 ZnO 的摩尔比为 2.5%时表现出最佳性能，短路电流密度（Jsc）为 3.24 mA cm(-2)，PCE 为 0.25%，明显高于没有 Ga 掺杂的情况。此外，使用电化学沉积的 ZnO 粉末缓冲的 Cu2O 从混合 Cu(2+)-ZnO 粉末溶液和氧等离子体处理可以降低异质结界面处的缺陷态密度，进一步将 Jsc 和 PCE 提高到 4.86 mA cm(-2)和 0.34%，分别是所有全电化学制造的 Cu2O-ZnO NW 太阳能电池中最高的功率转换效率。这种方法为使用低成本的溶液法大规模制造高性能的 Cu2O-ZnO NW 太阳能电池提供了巨大的潜力。
