Improved short-circuit current density in bulk heterojunction solar cells with reduced graphene oxide-germanium dioxide nanocomposite in the photoactive layer
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In the quest to improve the optical absorption and electrical transport of poly-3-hexylthiophene (P3HT) and (6-6) phenyl-C61-butyric acid methyl ester (PCBM) blend film, reduced graphene oxide-germanium dioxide nanocomposite (rGO-GeO2) was employed in the photoactive layer of thin film organic solar cells. Bulk heterojunction solar cells (BHJ SCs) with rGO-GeO2 composite in the active layer exhibited an increase in power conversion efficiency (PCE) of up to 53%. Significant improvement in the measured photocurrent is achieved by the incorporation of rGO-GeO2 in the active layer. High short-circuit current density (Jsc) of up to 17 mA/cm2 is attained in the BHJ SCs. The high Jsc shows that the inlay of rGO-GeO2 in the active layer facilitates exciton separation and creates percolation pathways for charge transport to the electrodes. Charge separation is energetically favoured by a built-in potential difference between the donor and acceptor phases of the active layer. Hence, the incorporation of rGO-GeO2 composite in the active layer improves its charge photogeneration, separation and transport to yield high Jsc and enhanced PCE.
Author Affiliation: Egerton University
Amollo, T. A., Mola, G. T., & Nyamori, V. O. (2020). Improved short-circuit current density in bulk heterojunction solar cells with reduced graphene oxide-germanium dioxide nanocomposite in the photoactive layer. Materials Chemistry and Physics, 254, 123448. https://doi.org/10.1016/j.matchemphys.2020.123448