Characterization of the structural, optical and electrical properties of ZnO:re3+/FWCNT/P3HT nanocomposite for possible application in organic solar cells

Abstract

The structure, morphology, optical, and electrical characteristics of rare earth (RE) metal ions, few-walled carbon nanotubes (FWCNT) and zinc oxide (ZnO) nanocomposite for possible applications such as electron acceptor in the active layer of organic solar cells are described in this study. ZnO nanotubes were created utilizing a microwave-assisted sol-gel technique with 1-Thioglycerol (TG) as a capping agent. To explore the effect of dopants in ZnO nanorods, the amounts of impurities or dopants were changed and integrated into a conjugated virgin poly(3-hexylthiophene) polymer (P3HT). The surface morphology, crystal structure, optical absorption, photoluminescence (PL) and current-voltage (I-V) properties were influenced by dopants, ZnO/FWCNT nanocomposite and the incorporation of P3HT. The Field emission scanning electron microscopy (FE-SEM) showed the homogeneous nanorods morphology of ZnO, and the inclusion of P3HT dispersed the morphology into mixed structures of nanorods. X-ray diffraction (XRD) results showed that ZnO despite being doped or incorporated with P3HT, the nanorods have hexagonal wurtzite structure. X-ray photoelectron spectroscopy (XPS) revealed a strong interaction between P3HT and ZnO. All of the functional groups in the materials were visible using Fourier-transform infrared (FTIR). P3HT-ZnO doped with rare earth ions and P3HT/ZnO/FWCNT have a good property of the interaction that leads to a good mixing of ligands. The UV/VIS/NIR absorption findings demonstrated a significant improvement in absorption, providing additional chances for improved efficiency in organic solar cells. This is due to an increase in doping concentration and the integration of P3HT-ZnO at various ratios. The photoluminescence quenching effect of PL was considerable, suggesting that it might be used as an electron acceptor in the active layer of an organic photovoltaic (OPV) system. The I-V curve demonstrated an increase in electrical conductivity, indicating that these materials (P3HT-ZnO) at different ratios, an increase in rare earth doping concentration, and FWCNT) are prime candidates for accelerating electron transport, lowering electron-hole recombination, and improving the efficiency of organic solar cells (OSCs). In this work, rare earth ions and FWCNT doped ZnO were combined with P3HT, and the introduction of P3HT considerably reduces the PL intensity, indicating a charge transfer between donor and acceptor materials. This combination serves to specifically amplify and enhance electron transfer and electrical conductivity for possible use in OSCs. Moreover, this combination of materials has a strong photoluminescence quenching effect indicating a good charge separation in the photoactive layer of the organic solar cell device.