NO₂-induced performance enhancement of PEDOT:PSS/Si hybrid solar cells with a high efficiency of 13.44%

Using poly (3,4-ethylene-dioxythiophene): poly(styrenesulfonate) (PEDOT:PSS) as an effective hole collecting layer, high-efficiency PEDOT:PSS/n-Si hybrid solar cells are fabricated and a power conversion efficiency (PCE) of 12.13% is obtained. After being treated by HNO₃ vapor, the PCE value of PEDOT:PSS/n-Si hybrid solar cells enhances from 12.13% to 13.44%. NO₂ gas molecules in HNO₃ vapor play a significant doping role in raising the PCE of solar cells. As the doping level raises, NO₂ would get more electrons from PEDOT and lead to the increase of hole carriers in the films, which improves the polymer film's conductivity and PCE of solar cells.