Evaluation of rr-P3HT solar cells with low amounts of SiNWs

Abstract

Photoactive hybrid layers of material combinations such as region-regular poly (3-hexylthiophene), i.e. rr-P3HT and silicon nanowires (SiNWs) have been extensively studies over the past decades. However, these hybrid layers still require further exploration as candidates for solar cell fabrications due to the scarcity of fundamental understanding of the mechanisms that govern the charges migration within layers, which might be limiting the full potential of these materials. In this study, we synthesised SiNWs via metal assisted chemical etching (MACE) and incorporated different weight ratios of as-synthesised wires with rr-P3HT, in blended form to fabricate solar cells. These materials were employed due to favourable charge carrier mobility and good optical absorption associated with them respectively. These photovoltaic devices were characterised by current–voltage (I-V) measurement under illumination, and interpreted on the basis of charge transfer due to different SiNW concentrations. Morphology characterisation shows that the SiNWs are randomly distributed across the active area, and that the film becomes progressively inhomogeneous upon excess addition of SiNWs. The UV–Vis and PL spectra suggest changes in absorption and emission characteristics upon SiNW incorporation into the rr-P3HT blended matrix, which assist with the interpretation of the charge transfer mechanism.