Hybrid tapered silicon nanowire/PEDOT:PSS solar cells

Abstract

A tapered silicon nanowire array (TSiNWs)/poly(3,4-ethylenedioxythiophene)/poly(styrenesulfonate) (PEDOT:PSS) hybrid solar cell was obtained based on alkali treatment processing. TSiNWs are engineered by combining electroless etching and an alkali solution in which the morphology of the tapered nanowire can be controlled by changing the immersing time. The results show that the alkali treatment could taper the silicon nanowires so that the polymer could conformally infiltrate into SiNWs via spin-coating. The experimental results demonstrate that the length and morphology of the SiNWs are key factors for improving the cell performance. Compared to the SiNWs/polymer hybird device, the TSiNWs/polymer hybrid solar cell can achieve a high power conversion efficiency of 6.87% and short-circuit current density of 26.7 mA cm⁻². Therefore, tapered silicon nanowires are promising structures for realizing economically viable hybrid solar cells based on a very simple, scalable, and low-cost solution route.