Organic-inorganic hybrid tandem multijunction photovoltaics with extended spectral response

We demonstrate series-connected hybrid tandem multijunction photovoltaics by combining hydrogenated amorphous silicon (a-Si:H) and polymer-based organic photovoltaics (OPVs). To utilize the wide solar spectrum with cost-effective processes, we employed a solution-processed low band gap OPV subcell onto the a-Si: H subcell. The interfacial contact between the subcells strongly affects the photovoltaic performance of the tandem cells. By using MoO(3) as an efficient hole transporting intermediate layer instead of the conventional conducting polymer, we obtained power conversion efficiency of 1.84% and open-circuit voltage (V(OC)) of 1.50 V which corresponds closely to the sum of V(OC)s of the subcells. (C) 2011 American Institute of Physics. [doi:10.1063/1.3580609]