Organic and solution-processed tandem solar cells with 17.3% efficiency

• Published in: Science (American Association for the Advancement of Science) Vol. 361; no. 6407; pp. 1094 - 1098
• Main Authors: Meng, Lingxian, Zhang, Yamin, Wan, Xiangjian, Li, Chenxi, Zhang, Xin, Wang, Yanbo, Ke, Xin, Xiao, Zuo, Ding, Liming, Xia, Ruoxi, Yip, Hin-Lap, Cao, Yong, Chen, Yongsheng
• Format: Journal Article
• Language: English
• Published: United States The American Association for the Advancement of Science 14.09.2018
• Subjects: Charge materials; Efficiency; Electromagnetic absorption; Empirical analysis; Energy conversion efficiency; Organic materials; Organic semiconductors; Photovoltaic cells; Photovoltaics; Solar cells; Thickness
• ISSN: 0036-8075; 1095-9203; 1095-9203
• DOI: 10.1126/science.aat2612

Tandem solar cells can boost efficiency by using a wider range of the solar spectrum. The bandgap of organic semiconductors can be tuned over a wide range, but, for a two-terminal device that directly connects the cells, the currents produced must be nearly equal. Meng et al. used a semiempirical analysis to choose well-matched top- and bottom-cell active layers. They used solution processing to fabricate an inverted tandem device that has a power conversion efficiency as high as 17.4%. Science , this issue p. 1094 A semi-empirical analysis helped to optimize materials for a tandem organic solar cell with high power conversion efficiency. Although organic photovoltaic (OPV) cells have many advantages, their performance still lags far behind that of other photovoltaic platforms. A fundamental reason for their low performance is the low charge mobility of organic materials, leading to a limit on the active-layer thickness and efficient light absorption. In this work, guided by a semi-empirical model analysis and using the tandem cell strategy to overcome such issues, and taking advantage of the high diversity and easily tunable band structure of organic materials, a record and certified 17.29% power conversion efficiency for a two-terminal monolithic solution-processed tandem OPV is achieved.