Morphological device model for organic bulk heterojunction solar cells.

Maturová, K; van Bavel, S S; Wienk, M M; Janssen, R A J; Kemerink, M · Nano Lett · 2009

basic_science · Level V

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Abstract

We present a numerical model for calculating current-voltage characteristics of polymer:fullerene bulk hetrojunction solar cells at different degrees of nanoscale phase separation. We show that the short-circuit current enhancement with finer phase separation is due to a reduction in bimolecular recombination caused by lateral movement of photogenerated electrons to the fullerene-rich phase. At high bias, vertical electron transport is enhanced and lateral movement is reduced, causing a significant field-dependent carrier extraction for coarse morphologies.