Park Song Yi, Song Seyeong, Yoon Yung Jin, Lee Tack Ho, An Na Gyeong, Walker Bright, Kim Jin Young
Department of Energy Engineering, Ulsan National Institute of Science and Technology (UNIST) Ulsan 44919 South Korea
Department of Chemistry, Kyung Hee University Seoul 02447 South Korea
RSC Adv. 2018 Nov 28;8(69):39777-39783. doi: 10.1039/c8ra08317g. eCollection 2018 Nov 23.
The ability to control the morphologies of active layers is a critical factor in the successful development of polymer solar cells (PSCs), and solvent processing additives offer a simple and effective way to accomplish this. In particular, diphenyl ether (DPE) is one of the most effective solvent additives but analogous additives based on this structure have not yet been extensively investigated. In this work, we have fabricated PSCs and investigated photovoltaic device characteristics using the series of non-halogenated, diphenyl-chalcogen solvent additives; DPE, diphenyl sulfide (DPS) and diphenyl selenide (DPSe). DPS devices showed optimal power conversion efficiencies (PCEs) of up to 9.08%, and DPE devices also showed similarly high PCEs of up to 8.85%. In contrast, DPSe devices showed relatively low PCEs (5.45% at best) which we attribute to significant surface recombination and high series resistance, which led to limited open-circuit voltage ( ). In the case of DPS, fast, field-independent photocurrent saturation with negligible bimolecular recombination led to efficient charge separation and collection, which resulted in the highest PCEs. Additionally, using 1,2,4-trimethylbenzene and DPS as an entirely non-halogenated solvent/additive system, we successfully demonstrated device fabrication with comparably high PCEs of up to 8.4%. This work elucidates the effects of diphenyl-based solvent additives in PSCs and suggests a great potential of DPS as an effective non-halogenated solvent additive.
控制活性层的形态是聚合物太阳能电池（PSC）成功开发的关键因素，而溶剂加工添加剂提供了一种简单有效的实现方法。特别是，二苯醚（DPE）是最有效的溶剂添加剂之一，但基于这种结构的类似添加剂尚未得到广泛研究。在这项工作中，我们制备了PSC，并使用一系列非卤代的二苯基硫族溶剂添加剂（DPE、二苯硫醚（DPS）和二苯硒醚（DPSe））研究了光伏器件的特性。DPS器件的最佳功率转换效率（PCE）高达9.08%，DPE器件也显示出高达8.85%的类似高PCE。相比之下，DPSe器件的PCE相对较低（最高为5.45%），我们将其归因于显著的表面复合和高串联电阻，这导致开路电压受限。在DPS的情况下，快速、与场无关的光电流饱和且双分子复合可忽略不计，导致有效的电荷分离和收集，从而产生了最高的PCE。此外，使用1,2,4-三甲基苯和DPS作为完全非卤代的溶剂/添加剂体系，我们成功展示了制备出PCE高达8.4%的器件。这项工作阐明了二苯基溶剂添加剂在PSC中的作用，并表明DPS作为一种有效的非卤代溶剂添加剂具有巨大潜力。
