Reversed organic-inorganic hybrid tandem solar cells for improved interfacial series resistances and balanced photocurrents

We report a promising approach to fabricate organic-inorganic hybrid tandem photovoltaic devices with a reversed configuration. High bandgap hydrogenated amorphous silicon (a-Si:H) was deposited with plasma-enhanced chemical vapor deposition onto a solution-processed low bandgap organic photovoltaic (OPV) subcell. Two important factors for efficient tandem solar cells, interfacial series resistance (R-S,R-int) and balanced photocurrents, were investigated. The intimate interfacial contact eliminated the R-S,R-int, and sufficient transmittance of the OPV front subcell led to the well-balanced photocurrents. As a result, this reversed hybrid tandem device showed an enhanced efficiency of 3.3% and an open-circuit voltage of 1.51 V