Sensitizers with rigidified-aromatics as the conjugated spacers for dye-sensitized solar cells

Abstract

Metal-free dye sensitized solar cells emerged as an important source of a renewable energy resource because of low production, simple fabrication process and a wide availablility of organic dyes. This review mainly focuses on metal-free sensitizers having rigidifed-aromatics as the conjugated spacer for applications in DSSCs. Based on their structures dyes have been divided into three major subsegments: (i) ladder type polyphenylenes with or without heteroatoms; (ii) rigidfied-aromatics as a donor segments; (iii) fused polyaromatics. Planarization of organic molecules through rigidification of aromatics allows effective communication and their smaller reorganization energy is beneficial to photoinduced charge transfer. Dyes having rigidified aromatics as a conjugated spacer emerged as promising candidates and a maximum efficiency of 12.5 % has been achieved with DSSCs without coadsorbate or co-sensitizer.

Significant light absorption enhancement by a single heterocyclic unit change in the π-bridge moiety from thieno[3,2-b]benzothiophene to thieno[3,2-b]indole for high performance dye-sensitized and tandem solar cells

“…2a, 9 On the basis of this concept, Eom et al reported the thieno[3,benzothiophene (TBT) moiety as a new πbridge in organic sensitizers (SGT-130, Figure 1), exhibiting a relatively good PCE of 10.47%. 2a, 9 On the basis of this concept, Eom et al reported the thieno[3,benzothiophene (TBT) moiety as a new πbridge in organic sensitizers (SGT-130, Figure 1), exhibiting a relatively good PCE of 10.47%.…”

“…2a, 9 On the basis of this concept, Eom et al reported the thieno[3,benzothiophene (TBT) moiety as a new πbridge in organic sensitizers (SGT-130, Figure 1), exhibiting a relatively good PCE of 10.47%. The strategies to improve the π-bridge ability can be defined by: (i) extending the conjugation length of the πbridge, 9,13 (ii) substituting the bridging atom in a fused-ring π-bridge, 14 and (iii) increasing the electron-donating ability of the donor 15 . The strategies to improve the π-bridge ability can be defined by: (i) extending the conjugation length of the πbridge, 9,13 (ii) substituting the bridging atom in a fused-ring π-bridge, 14 and (iii) increasing the electron-donating ability of the donor 15 .…”

Aggregation‐Free Organic Dyes Featuring Spiro[dibenzo[3,4:6,7]cyclohepta[1,2‐b]quinoxaline‐10,9′‐fluorene] (SDBQX) for Dye‐Sensitized Solar Cells

“…Many chemists put their eyes on organic dyes because of their advantages such as low cost, low toxicity, easy structural modification and even efficiency predictable . Many kinds of excellent organic dyes have been developed, such as porphyrin dyes, N ‐annulated perylene dyes, and many different kinds of rigidified aromatics dyes . Dyes with D–π–A system is the main type organic dyes, which contains an electron donor (D), an electron acceptor (A), and a π‐conjugated spacer (π) to link the donor and acceptor .…”

Metal-Free Sensitizers for Dye-Sensitized Solar Cells

“…Without the use of any coadsorbent, a sensitizer consisting of an N‐annulated indenoperylene donor and a secondary acceptor achieved a record efficiency of 12.5%, which surpassed the champion dye YD2‐o‐C8 8. Sensitizers with rigidified aromatic segments as the conjugated spacer were recently reviewed by us 37. Our first attempt to use a rigidified segment was the fluorene entity.…”