The present work aims to obtain composites of two semiconductor materials, poly(3-hexylthiophene) (P3HT) and cobalt oxide (Co3O4), by in situ synthesis using the Sugimoto method. Both materials serve as hole-transport layers (HTL) in photovoltaic devices. The objective is to understand the effect of Co3O4 nanoparticles on P3HT, particularly how they interact and potentially alter the polymer’s electronic structure. Co3O4 nanoparticles were synthesized by chemical precipitation as a byproduct of thin-film formation. They were incorporated at different concentration weight ratios (P3HT/Co3O4:1/0.03, 1/0.05, and 1/0.08) into the P3HT/Co3O4 composite. Their influence on the optoelectronic properties was analyzed. P3HT/Co3O4 films were characterized by various techniques: morphological (SEM, TEM, and AFM) and optoelectronic (FTIR and photoluminescence). The objective of the resulting composite is to improve HTL performance in a solar cell. Additionally, a DFT+U computational study was performed to investigate the P3HT adsorption on the Co3O4(110) surface. Three configurations showed that Co–S bond formation and ligand-to-metal charge transfer are the primary interactions, with van der Waals forces contributing significantly to the adsorption energy. Overall, the effect of cobalt oxide on P3HT was investigated experimentally and theoretically, contributing to a deeper understanding of the interfacial electronic interactions in P3HT/Co3O4 systems beyond conventional structural and optoelectronic analyses.
Hernández-Martínez et al. (2026) studied this question.