Fabrication of carbon nanotube hybrid films as transparent electrodes for small-molecule photovoltaic cells

Abstract

We demonstrate stable carbon nanotube (CNT) hybrid films as transparent electrodes for small-molecule photovoltaic cells. A photonic curing process is utilized to enhance the doping, and construct CNT hybrid films with solution-processed CuI and evaporated MoO₃, respectively. These novel CNT–CuI and CNT–MoO₃ hybrid films exhibit stable sheet resistances of 70 and 110 Ω per square at around 80% transmittance, respectively. OPV cells are fabricated by evaporating a tetraphenyldibenzoperiflanthene and fullerene bilayer heterojunction on a series of CNT hybrid films. The corresponding optimization of OPV cells are carried out on CNT–CuI and CNT–MoO₃ hybrid films. The correlations between the cell performance and the surface morphology, sheet resistance and transmittance of these CNT hybrid films are discussed in detail. The optimum cell on the CNT–CuI film with a nanostructured cascade-type architecture exhibits a power conversion efficiency of 2.97%.