P3HT:spiro-OMeTAD blending system as a hole conductor for solid-state hybrid solar cells with a dendritic TiO2/Sb2S3 nanorod composite structure

Abstract

A hybrid solar cell (HSC) based on a solution-processable binary blend of poly(3-hexylthiophene-2,5-diyl) and 2,2′,7,7′-tetrakis-(N,N-di-p-methoxyphenylamine)-9,9′-spirobifluorene (P3HT:spiro-OMeTAD) with a dendritic TiO₂/Sb₂S₃ nanorod composite film was successfully fabricated for the first time. The sparse dendritic TiO₂ structure was beneficial for the growth of Sb₂S₃ nanorods in the adjacent dendritic TiO₂ structure. Owing to the well-matched energy levels of TiO₂, Sb₂S₃, P3HT, and spiro-OMeTAD, electrons were effectively separated and transported. The HSC assembled of TiO₂/Sb₂S₃/P3HT:spiro-OMeTAD/Au composite films achieved a highest power conversion efficiency (PCE) of 1.53%, and the corresponding stability was investigated over one month.