Enhanced Photocurrent Quantum Yield by Electronic Interaction between Zinc Porphyrin and Rhodamine B Molecules in Al/Dye/Au Sandwich-Type Solar Cell

Abstract

The enhanced photocurrent is observed with the mixed solid of 5,10,15,20-tetraphenylporphyrinatozinc (Zntpp) and rhodamine B (RhB) compared with the pure Zntpp and RhB solids in Al/dye/Au sandwich-type solar cell. The photocurrent quantum yield has a maximum at the mixing ratio (R) of 0.5−0.8 defined as the molar ratio of porphyrin to total dye. The enhancement arises from the decrease of the series resistance by 2 orders of magnitude upon mixing Zntpp and RhB for the best cells. For the Al/mixed solid (R = 0.57)/Au cell, the short-circuit photocurrent quantum yield (φ) of 14.7%, the open-circuit photovoltage (Voc) of 0.90 V, the fill factor (ff) of 0.18, and the energy conversion yield (η) of 0.82% are obtained when illuminated with 440 nm monochromatic light of 14.7 μW cm-2 intensity at the Al/dye interface, and the values of φ = 9.1%, Voc = 0.90 V, ff = 0.19, and η = 0.72% are obtained when the sample is illuminated with 570 nm monochromatic light of 32.4 μW cm-2 intensity. It is found from the absorpt...