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-52 -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. © 2006 American Institute of Physics. DOI: 10.1063/1.2408641