Inaba Shusei, Vohra Varun
Department of Engineering Science, University of Electro-Communications, Chofu 182-8585, Japan.
Materials (Basel). 2017 May 9;10(5):518. doi: 10.3390/ma10050518.
Polymer solar cells (PSCs) are considered as one of the most promising low-cost alternatives for renewable energy production with devices now reaching power conversion efficiencies (PCEs) above the milestone value of 10%. These enhanced performances were achieved by developing new electron-donor (ED) and electron-acceptor (EA) materials as well as finding the adequate morphologies in either bulk heterojunction or sequentially deposited active layers. In particular, producing adequate vertical concentration gradients with higher concentrations of ED and EA close to the anode and cathode, respectively, results in an improved charge collection and consequently higher photovoltaic parameters such as the fill factor. In this review, we relate processes to generate active layers with ED-EA vertical concentration gradients. After summarizing the formation of such concentration gradients in single layer active layers through processes such as annealing or additives, we will verify that sequential deposition of multilayered active layers can be an efficient approach to remarkably increase the fill factor and PCE of PSCs. In fact, applying this challenging approach to fabricate inverted architecture PSCs has the potential to generate low-cost, high efficiency and stable devices, which may revolutionize worldwide energy demand and/or help develop next generation devices such as semi-transparent photovoltaic windows.
聚合物太阳能电池（PSCs）被认为是可再生能源生产中最具前景的低成本替代方案之一，目前其器件的功率转换效率（PCEs）已超过10%这一里程碑值。这些性能的提升是通过开发新型电子供体（ED）和电子受体（EA）材料，以及在体异质结或顺序沉积的活性层中找到合适的形貌来实现的。特别是，分别在靠近阳极和阴极处产生具有较高浓度的ED和EA的适当垂直浓度梯度，会导致电荷收集得到改善，从而提高诸如填充因子等光伏参数。在本综述中，我们阐述了产生具有ED-EA垂直浓度梯度的活性层的过程。在总结通过退火或添加剂等过程在单层活性层中形成这种浓度梯度之后，我们将验证多层活性层的顺序沉积可以是一种显著提高PSCs的填充因子和PCE的有效方法。事实上，将这种具有挑战性的方法应用于制造倒置结构的PSCs有可能生产出低成本、高效率和稳定的器件，这可能会彻底改变全球能源需求和/或有助于开发下一代器件，如半透明光伏窗。
