Bulk-Heterojunction Solar Cells Based on Mixed Donorsof P3HT and Phenylene–Thiophene Oligomer Derivative

Abstract

Two donors with different spectral sensitivities and an accepter were used to fabricate bulk hetero-junction (BHJ) solar cells with a wider absorption range. In this research, ultraviolet and visible spectra of two donors: poly(3-hexylthiophene) (P3HT) and 3,7-bis [5-(4-n -hexylphenyl)-2-thienyl] dibenzothiophene -5, 5-dioxide (37HPTDBTSO) and accepter: [6,6]-phenyl C61 butyric acid methyl ester (PCBM) in the forms of solutions or films were investigated. Based on these results, BHJ solar cells were fabricated using a ternary mixed solution of P3HT, 37HPTDBTSO, and PCBM. The measured incident photon to charge carrier efficiency spectra indicated that the solar cell based on the two donors showed a wider spectral sensitivity range. The open circuit voltage V oc was also improved to be 0.63 V, and a short circuit current density J sc was 3.65 mA/cm 2 , and a power conversion efficiency was 0.81%.