Exciton splitting and carrier transport across the amorphous-silicon/polymer solar cell interface

The authors study exciton splitting at the interface of bilayer hybrid solar cells to better understand the physics controlling organic-inorganic device performance. Hydrogenated amorphous silicon (a-Si:H)/poly(3-hexylthiophene) (P3HT) and a-Si:H/poly(2-methoxy-5-(2(')-ethyl-hexyloxy)-1,4-phenylenevinylene) (MEH-PPV) solar cells show photoresponse dominated by exciton production in the polymer. The a-Si:H/P3HT devices are nearly as efficient as titania/P3HT cells. However, the a-Si:H/MEH-PPV system has much lower photocurrent than a-Si:H/P3HT, likely due to inefficient hole transfer back to the MEH-PPV after energy transfer from MEH-PPV to a-Si:H. (c) 2006 American Institute of Physics.