摘要
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 CH_3NH_3PbI_(3-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.
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CH_3NH_3PbI_(3-x)Cl_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CH_3NH_3PbI_(3-x)Cl_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.
基金
funded by the National Natural Science Foundation of China (91333204 and 21325419)
the Chinese Academy of Sciences (CAS) (XDB12030200)
CAS-Croucher Funding Scheme for Joint Laboratories for their support
