CdTe Nanocrystal Hetero-Junction Solar Cells with High Open Circuit Voltage Based on Sb-doped TiO(2) Electron Acceptor Materials

We propose Sb-doped TiO(2) as electron acceptor material for depleted CdTe nanocrystal (NC) hetero-junction solar cells. Novel devices with the architecture of FTO/ZnO/Sb:TiO(2)/CdTe/Au based on CdTe NC and TiO(2) precursor are fabricated by rational ambient solution process. By introducing TiO(2) with dopant concentration, we are able to tailor the optoelectronic properties of NC solar cells. Our novel devices demonstrate a very high open circuit voltage of 0.74 V, which is the highest V(oc) reported for any CdTe NC based solar cells. The power conversion efficiency (PCE) of solar cells increases with the increase of Sb-doped content from 1% to 3%, then decreases almost linearly with further increase of Sb content due to the recombination effect. The champion device shows J(sc), V(oc), FF, and PCE of 14.65 mA/cm(2), 0.70 V, 34.44, and 3.53% respectively, which is prospective for solution processed NC solar cells with high V(oc).