The Light‐Induced Field‐Effect Solar Cell Concept – Perovskite Nanoparticle Coating Introduces Polarization Enhancing Silicon Cell Efficiency

• Published in: Advanced materials (Weinheim) Vol. 29; no. 18
• Main Authors: Wang, Yusheng, Xia, Zhouhui, Liu, Lijia, Xu, Weidong, Yuan, Zhongcheng, Zhang, Yupeng, Sirringhaus, Henning, Lifshitz, Yeshayahu, Lee, Shui‐Tong, Bao, Qiaoliang, Sun, Baoquan
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 01.05.2017
• Subjects: Alignment; Asymmetry; Coating effects; Conducting polymers; Crystal pulling; Crystal structure; Efficiency; Electric contacts; Energy conversion efficiency; Energy gap; Energy management; field effect; Light; Light reflection; light‐induced; Materials science; Molecular structure; Nanoparticles; perovskite nanoparticles; Photovoltaic cells; Polarization; Silicon; Silicon wafers; solar cells; Sunlight; Wave reflection; perovskite nanoparticles; light-induced; polarization; solar cells; field effect
• ISSN: 0935-9648; 1521-4095
• DOI: 10.1002/adma.201606370

Solar cell generates electrical energy from light one via pulling excited carrier away under built‐in asymmetry. Doped semiconductor with antireflection layer is general strategy to achieve this including crystalline silicon (c‐Si) solar cell. However, loss of extra energy beyond band gap and light reflection in particular wavelength range is known to hinder the efficiency of c‐Si cell. Here, it is found that part of short wavelength sunlight can be converted into polarization electrical field, which strengthens asymmetry in organic‐c‐Si heterojunction solar cell through molecule alignment process. The light harvested by organometal trihalide perovskite nanoparticles (NPs) induces molecular alignment on a conducting polymer, which generates positive electrical surface field. Furthermore, a “field‐effect solar cell” is successfully developed and implemented by combining perovskite NPs with organic/c‐Si heterojunction associating with light‐induced molecule alignment, which achieves an efficiency of 14.3%. In comparison, the device with the analogous structure without perovskite NPs only exhibits an efficiency of 12.7%. This finding provides a novel concept to design solar cell by sacrificing part of sunlight to provide “extra” asymmetrical field continuously as to drive photogenerated carrier toward respective contacts under direct sunlight. Moreover, it also points out a method to combine promising perovskite material with c‐Si solar cell. A “field‐effect solar cell” is successfully demonstrated by combining perovskite nanoparticles with organic/c‐Si heterojunction associating with light‐induced molecule alignment. This provides a novel concept to design efficient solar cell by sacrificing part of sunlight to provide “extra” asymmetrical field continuously as to drive photogenerated carrier toward respective contacts under direct sunlight.