Design of triangular gratings for thin film Si/PEDOT:PSS heterojunction solar cells

Flexible thin-film crystalline silicon/poly(3, 4-ethylenedioxythiophene): poly(styrene sulfonate) (PEDOT:PSS) heterojunction solar cells (HSCs)have attracted much attention, due to presenting the both merits of organic semiconductor (i.e. easy-manufacture and low-cost) and inorganic semiconductor with the excellent photoelectric properties. The indirect semiconductor c-Si has a low optical absorption coefficient, so the light-trapping structures on the silicon surface are need to improve the photocurrent density (Jph) of HSCs. In this paper, for improving the optical adsorption of c-Si thin film (2 μm), solving the Maxwell's basic equations by finite element method, the influence of one-dimensional (1-D) triangular gratings on the optical absorption, photocurrent density and electric field distribution of Si/PEDOT:PSS HSCs are investigated systematically. Double-sided 1-D triangular grating is designed to improve the light harvesting in the thin film Si/PEDOT: PSS HSCs, receiving a high power conversion efficiency of over 15%.Therefore, 1-D triangular gratings is used to effectively manage the optical absorption of c-Si thin-film, furthermore, the conformal heterojunction of Si/PEDOT: PSS is easily formed as a basis for the high efficiency flexible HSCs. © 2019, Editorial Board of Acta Energiae Solaris Sinica. All right reserved.