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Metal‐Free Sensitizers for Dye‐Sensitized Solar Cells
Author(s) -
Chaurasia Sumit,
Lin Jiann T.
Publication year - 2016
Publication title -
the chemical record
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.61
H-Index - 78
eISSN - 1528-0691
pISSN - 1527-8999
DOI - 10.1002/tcr.201500288
Subject(s) - dye sensitized solar cell , photoexcitation , chemistry , photochemistry , electron transfer , redox , electron acceptor , iodide , acceptor , organic chemistry , physics , electrode , nuclear physics , electrolyte , excited state , condensed matter physics
This review focuses on our work on metal‐free sensitizers for dye‐sensitized solar cells (DSSCs). Sensitizers based on D−A′−π−A architecture (D is a donor, A is an acceptor, A′ is an electron‐deficient entity) exhibit better light harvesting than D−π−A‐type sensitizers. However, appropriate molecular design is needed to avoid excessive aggregation of negative charge at the electron‐deficient entity upon photoexcitation. Rigidified aromatics, including aromatic segments comprising fused electron‐excessive and ‐deficient units in the spacer, allow effective electronic communication, and good photoinduced charge transfer leads to excellent cell performance. Sensitizers with two anchors/acceptors, D(–π–A) 2 , can more efficiently harvest light, inject electrons, and suppress dark current compared with congeners with a single anchor. Appropriate incorporation of heteroaromatic units in the spacer is beneficial to DSSC performance. High‐performance, aqueous‐based DSSCs can be achieved with a dual redox couple comprising imidazolium iodide and 2,2,6,6‐tetramethylpiperidin‐ N ‐oxyl, and/or using dyes of improved wettability through the incorporation of a triethylene oxide methyl ether chain.