经过几十年的发展，有机太阳能电池的各项参数已经得到明显的提高，其中外量子效率高达80%，填充因子高达80%，单层异质结电池的光电转换效率已经超过14%。低开路电压已成为制约太阳能电池光电转换效率进一步提高的关键因素。光伏器件中形成电荷转移态的损失和载流子复合损失是限制开路电压的主要因素。但是抑制电荷分离损失的同时往往伴随着外量子转换效率的降低。材料学家面临着一个强大的挑战：设计新的光伏材料满足给受体材料之间的能级需求来最小化开路电压与短路电流之间的折中关系。这也是此领域的研究热点和难点。本研究工作立足于设计合成一系列基于苯并三氮唑衍生物的小分子受体材料。通过改变材料的中间单元，封端基团，桥连单元以及烷基链，系统性的研究其中的结构—性质—性能关系，从而设计获得基于苯并三氮唑的高电压高短路电流的小分子非富勒烯电子受体材料。这将对进一步提高太阳能电池转化效率具有非常重要的理论和实践意义。

The organic solar cells (OSCs) have been highly optimized over the past few decades. As a result, the external quantum efficiencies (EQEs) reaching 80%, and fill factors (FFs) close to 80%, as well as the power conversion efficiencies (PCEs) over 14% for single junction organic photovoltaic (PV) devices have been achieved. The limiting parameter for achieving higher PCEs remains the low open-circuit voltage (VOC). In the OSCs, a loss mechanism related to the charge transfer (CT) between electron donor (D) and electron acceptor (A), and the free carrier recombination losses usually significantly reduce the extractable photovoltage. In fact, suppressing charge separation energy loss may lead to the decrease of the EQEs. In this regard, synthetic chemists face a formidable challenge: to create new photovoltaic materials to manage the energetics between D and A and thus to minimize the trade-off between the VOC and short circuit current (JSC), which has always been the research hotspot and difficulty. Based on our previous studies on benzotriazole (BTA) based photovoltaic materials, herein, we plan to synthesize a series of BTA derivative to apply in the design of electron acceptors. By optimizing the center groups, end-capped groups, bridged units as well as solubilizing groups, we will systematically study the structure-property-performance relationship for the BTA based electron acceptors, and ultimately, obtain high performance non-fullerene organic solar cells with high VOC and large JSC. It will provide a theoretical basis and practical significance for the further improvement of the PCE of the OSCs.