Lead-sulphide quantum-dot sensitization of tin oxide based hybrid solar cells

We have fabricated infrared active hybrid solar cells composed of mesoporous SnO2 sensitized with PbS nanoparticles and infiltrated with organic hole-transporters, 2,2′,7,7′-tetrakis(N,N-di-p-methoxypheny-amine)-9,9′-spirobifluorene(spiro-OMeTAD) or poly(3-hexylthiophene). We observe photo-action to 1100 nm, peak quantum-efficiency over 20%, open-circuit voltages up to 0.5 V and power conversion efficiencies of over 0.5% under simulated sun light. As compared to solar cells composed of mesoporous TiO2 sensitized with the same PbS nanoparticles, the SnO2 based devices generate 4 times the photocurrent density under simulated sun light.