Enhanced Power Conversion Efficiency in Bumpy Structured Donor-Acceptor Interfaces via Polymer Blend

Abstract

We demonstrate a facile method to fabricate bilayer polymer solar cells with controlled hetrojunction structure by using polymer blend. Phase separation of poly(3-hexylthiophene)(P3HT) / insulating polymer blend film allows us to achieve a bumpy structure of electron donor layer. The deposition of [6, 6]-phenyl- C61-butyric acid methyl ester (PCBM) as electron acceptor layer formed an abrupt heterojunction structure. Bumpy structure solar cells exhibited enhancement of power conversion efficiencies compared to the solar cells based on flat interface structure, which is mainly attributed to the increase of photocurrent.