Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China.
School of Chemistry and Chemical Engineering, University of Chinese Academy of Sciences, Beijing, 100049, China.
Adv Mater. 2017 Jun;29(21). doi: 10.1002/adma.201606574. Epub 2017 Mar 21.
Inspired by the remarkable promotion of power conversion efficiency (PCE), commercial applications of organic photovoltaics (OPVs) can be foreseen in near future. One of the most promising applications is semitransparent (ST) solar cells that can be utilized in value-added applications such as energy-harvesting windows. However, the single-junction STOPVs utilizing fullerene acceptors show relatively low PCEs of 4%-6% due to the limited sunlight absorption because it is a dilemma that more photons need to be harvested in UV-vis-near-infrared (NIR) region to generate high photocurrent, which leads to the significant reduction of device transparency. This study describes the development of a new small-bandgap electron-acceptor material ATT-2, which shows a strong NIR absorption between 600 and 940 nm with an E of 1.32 eV. By combining with PTB7-Th, the as-cast OPVs yield PCEs of up to 9.58% with a fill factor of 0.63, an open-circuit voltage of 0.73 V, and a very high short-circuit current of 20.75 mA cm . Owing to the favorable complementary absorption of low-bangap PTB7-Th and small-bandgap ATT-2 in NIR region, the proof-of-concept STOPVs show the highest PCE of 7.7% so far reported for single-junction STOPVs with a high transparency of 37%.
受功率转换效率（PCE）显著提高的启发，有机光伏（OPV）的商业应用有望在不久的将来实现。最有前途的应用之一是半透明（ST）太阳能电池，它可以用于附加值应用，如能量收集窗。然而，利用富勒烯受体的单结 ST-O PVs 的 PCE 相对较低，为 4%-6%，这是因为由于更多的光子需要在紫外-可见-近红外（NIR）区域被吸收以产生高光电流，这导致器件透明度显著降低。本研究描述了一种新的小带隙电子受体材料 ATT-2 的开发，该材料在 600 至 940nm 之间具有很强的 NIR 吸收，E 值为 1.32eV。通过与 PTB7-Th 结合，铸膜 OPV 的 PCE 高达 9.58%，填充因子为 0.63，开路电压为 0.73V，短路电流非常高，为 20.75mA cm 。由于低带隙 PTB7-Th 和小带隙 ATT-2 在 NIR 区域的有利互补吸收，概念验证 ST-O PVs 显示出迄今为止单结 ST-O PVs 最高的 7.7%的 PCE，具有 37%的高透明度。
