High-Performance Ultrathin Organic–Inorganic Hybrid Silicon Solar Cells via Solution-Processed Interface Modification

5 years ago

High-Performance Ultrathin Organic–Inorganic Hybrid Silicon Solar Cells via Solution-Processed Interface Modification

Shuit-Tong Lee, Baohua Jia, Xuegong Yu, Xinlei Shen, Jie Zhang, Yinan Zhang, Baoquan Sun, Tao Song

Organic–inorganic hybrid solar cells based on n-type crystalline silicon and poly(3,4-ethylenedioxythiophene)–poly(styrenesulfonate) exhibited promising efficiency along with a low-cost fabrication process. In this work, ultrathin flexible silicon substrates, with a thickness as low as tens of micrometers, were employed to fabricate hybrid solar cells to reduce the use of silicon materials. To improve the light-trapping ability, nanostructures were built on the thin silicon substrates by a metal-assisted chemical etching method (MACE). However, nanostructured silicon resulted in a large amount of surface-defect states, causing detrimental charge recombination. Here, the surface was smoothed by solution-processed chemical treatment to reduce the surface/volume ratio of nanostructured silicon. Surface-charge recombination was dramatically suppressed after surface modification with a chemical, associated with improved minority charge-carrier lifetime. As a result, a power conversion efficiency of 9.1% was achieved in the flexible hybrid silicon solar cells, with a substrate thickness as low as ∼14 μm, indicating that interface engineering was essential to improve the hybrid junction quality and photovoltaic characteristics of the hybrid devices.

Publisher URL: http://dx.doi.org/10.1021/acsami.7b02140

DOI: 10.1021/acsami.7b02140