UV and aging effect on the degradation of PEDOT:PSS/nSi films for Hybrid Silicon solar cells

Abstract

Poly(3,4-ethylene-dioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) is one of the most successful conductive polymers, key component in different organic-based devices including silicon Hybrid Solar Cells (HSCs). However, there is limited information so far about the stability of this polymer under operation scenarios similar to those employed during performance, including UV irradiation or storage time. In this work, PEDOT:PSS thin layers have been spin coated onto silicon substrates, and their stability has been analysed under different conditions. Firstly, the influence under laser irradiation has been studied by Raman spectroscopy using both an UV-laser of 325 nm and a VIS-laser of 633 nm, with variable irradiation intensities and exposure time. Secondly, the effect of the removal of the native silicon oxide layer on the silicon substrate on the stability and passivation performance of the PEDOT:PSS has been analysed. Lastly, and closely related to its application in HSCs, the photoluminescence recombination has been analysed over storage time for 2 months to evaluate their real implementation as long-lasting solar cells.