Title: | High Performance Nanostructured Silicon−Organic Quasi p−n Junction Solar Cells via Low-Temperature Deposited Hole and Electron Selective Layer |
Authors: | Yuqiang Liu,† Zhi-guo Zhang,‡ Zhouhui Xia,† Jie Zhang,§ Yuan Liu,† Feng Liang,† Yongfang Li,‡ Tao Song,† Xuegong Yu,∥Shuit-tong Lee,† and Baoquan Sun*,† |
Institutions: | †Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, Suzhou 215123, China ‡Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China §Department of Electronic Engineering, The Chinese University of Hong Kong, New Territories, Hong Kong, China ∥State Key Laboratory of Silicon Materials and Department of Materials Science and Engineering, Zhejiang University, Hangzhou 310027, China |
Abstract: | Silicon−organic solar cells based on conjugated polymers such as poly(3,4-ethylenedioxy-thiophene):poly(styrenesulfonate) (PEDOT: PSS) on n-type silicon (n-Si) attract wide interest because of their potential for cost-effectiveness and high-efficiency. However, a lower barrier height (Φb) and a shallow built in potential (Vbi) of Schottky junction between n-Si and PEDOT:PSS hinders the power conversion efficiency(PCE) in comparison with those of traditional p−n junction. Here, a strong inversion layer was formed on n-Si surface by inserting a layer of 1, 4, 5, 8, 9, 11-hexaazatriphenylene hexacarbonitrile (HAT-CN), resulting in a quasi p−n junction. External quantum efficiency spectra, capacitance−voltage, transient photovoltage decay and minority charge carriers life mapping measurements indicated that a quasi p−n junction was built due to the strong inversion effect, resulting in a high Φb and Vbi. The quasi p−n junction located on the front surface region of silicon substrates improved the short wavelength light conversion into photocurrent. In addition, a derivative perylene diimide (PDIN) layer between rear side of silicon and aluminum cathodes was used to block the holes from flowing to cathodes. As a result, the device with PDIN layer also improved photoresponse at longer wavelength. A champion PCE of 14.14% was achieved for the nanostructured silicon−organic device by combining HAT-CN and PDIN layers. The low temperature and simple device structure with quasi p−n junction promises cost-effective high performance photovoltaic techniques. |
IF: | 13.344 |
Link: | http://pubs.acs.org/doi/pdf/10.1021/acsnano.5b05732 Editor: Danting Xiang |