Premium
Nanoscale Phase Separation and High Photovoltaic Efficiency in Solution‐Processed, Small‐Molecule Bulk Heterojunction Solar Cells
Author(s) -
Walker Bright,
Tamayo Arnold B.,
Dang XuanDung,
Zalar Peter,
Seo Jung Hwa,
Garcia Andres,
Tantiwiwat Mananya,
Nguyen ThucQuyen
Publication year - 2009
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.200900832
Subject(s) - materials science , organic solar cell , polymer solar cell , energy conversion efficiency , acceptor , fullerene , polymer , photovoltaic system , nanotechnology , small molecule , hybrid solar cell , heterojunction , chemical engineering , annealing (glass) , nanoscopic scale , optoelectronics , organic chemistry , composite material , ecology , chemistry , physics , genetics , engineering , biology , condensed matter physics
Research relating to organic solar cells based on solution‐processed, bulk heterojunction (BHJ) films has been dominated by polymeric donor materials, as they typically have better film‐forming characteristics and film morphology than their small‐molecule counterparts. Despite these morphological advantages, semiconducting polymers suffer from synthetic reproducibility and difficult purification procedures, which hinder their commercial viability. Here, a non‐polymeric, diketopyrrolopyrrole‐based donor material that can be solution processed with a fullerene acceptor to produce good quality films is reported. Thermal annealing leads to suitable phase separation and material distribution so that highly effective BHJ morphologies are obtained. The frontier orbitals of the material are well aligned with those of the fullerene acceptor, allowing efficient electron transfer and suitable open‐circuit voltages, leading to power conversion efficiencies of 4.4 ± 0.4% under AM1.5G illumination (100 mW cm −2 ). Small molecules can therefore be solution processed to form high‐quality BHJ films, which may be used for low‐cost, flexible organic solar cells.