文摘
In the past several years, conjugated polymers and organometal halide perovskites have become regarded as promising light-absorbing materials for next-generation photovoltaic devices and have attracted a great deal of interest. As the main part of this contribution, we describe the enhancement of near-infrared (NIR) photoresponse of well-known CH3NH3PbI3−x Cl x -based solar cells by the integration of bulk heterojunction (BHJ) small band gap polymer:fullerene absorbers. Particularly, the integration of a commercially available polymer PDPP3T and PCBM-based BHJ boosts the peak external quantum efficiency (EQE) by up to 46% in the NIR region (800−1000 nm), which is outside of the photoresponsive region (300−800 nm) of conventional perovskite solar cells. This substantial improvement in the EQE over the NIR region offers an additional current density of ∼5 mA cm−2 for the control perovskite solar cell, and a high power conversion efficiency (PCE) of over 12% was obtained in the perovskite/BHJ-based solar cells. In addition, the insertion of the BHJ absorber consisting of a small band gap polymer PDTP-DFBT and PCBM also results in nearly 40% EQE for the perovskite/BHJ solar cell. The results also reveal that controlling over the polymer/PCBM weight ratio for a BHJ absorber is the key to achieving the optimal efficiency for this type of perovskite-polymer hybrid solar cell. 中文摘要 近年来, 共轭聚合物和钙钛矿型有机金属卤化物被视为极具潜力的光伏材料, 引起了广泛的研究兴趣. 本文通过引入两种本体异质结(BHJ)聚合物: 富勒烯活性层, 大幅提高了基于CH3NH3PbI3−x 的钙钛矿太阳能电池的近红外光响应特性. 其中, 基于窄带隙聚合物PDPP3T的钙钛矿/BHJ杂化太阳能电池在近红外区域(800∼1000 nm)内的外量子效率(EQE)峰值高达46%, 且该区域已经超出了CH3NH3PbI3−x 型太阳能电池的光响应范围(300∼800 nm). 相较于参照的钙钛矿太阳能电池, 近红外区域大幅提升的EQE为钙钛矿/BHJ杂化太阳能电池贡献了额外的电流密度(∼5 mA cm−2), 因此其光电转换效率达到了12%以上. 此外, 引入基于聚合物PDTP-DFBT的BHJ也可以使钙钛矿太阳能电池在近红外区域的EQE达到40%以上. 研究结果也表明优化BHJ的聚合物: 富勒烯比例是提高这类钙钛矿-聚合物杂化太阳能电池性能的关键.