High photocurrent in oligo-thienylenevinylene-based small molecule solar cells with 4.9% solar-to-electrical energy conversion

Abstract

A set of five novel oligo-thienylenevinylene organic molecules have been synthesized and characterized for use as electron donor moieties in bulk-heterojunction solution-processed organic solar cells combined with PC71BM as an electron acceptor.

Cyclopentadithiophene-based co-oligomers for solution-processed organic solar cells

“…HornereWadswortheEmmons reaction of dialdehyde 5 [17] with the corresponding phosphonates 6 [18], 7 [19], and 8 [20] afforded central building blocks 9 [21], 10 [21], and 11 as trans-isomers according to NMR spectra ( 3 J trans ¼ 15.6 Hz). Subsequent VilsmeiereHaack formylation led to the corresponding dialdehydes 12 [21], 13 [21], and 14 after purification by chromatography column.…”

An investigation of the role acceptor side chains play in the processibility and efficiency of organic solar cells fabricated from small molecular donors featuring 3,4-ethylenedioxythiophene cores

“…When comparing the literature on other A-D-A molecule solar cells, the device performance for SAM-72:PC 71 BM is competitive with that of other EDOT-based molecules. 44,47,48,74,75 For example, the material reported by Antwi et al (DECA-2TE), with equivalent side chains and a similar core, showed J sc values reaching an average of 2.99 mA cm À2 and FF of 39%. 47 Likewise, another group of EDOT-based materials reported in 2013 gave solar cell device performances with all FF values < 50%.…”

“…44 Similarly, in the EDOT-based molecules reported by Montcada et al in 2013 (ref. 74) and 2015, 48 only two out of the six donor Fig. 4 Box plots for each optimization step for SAM-72:PC 71 BM devices:(a) donor to acceptor ratio, (b) thermal annealing temperature, and (c) thermal annealing + SVA time.…”

“…39 Although EDOT has been widely used as a p-linker in D-A type dyes in dye sensitized solar cells (DSSC), [40][41][42][43][44][45] to the best of our knowledge, EDOT-based small molecules for BHJ devices have largely utilized a D-A type architecture, 2,44,46 and relatively little has been focused on A-D-A architectures. 47,48 In this article, we report the synthesis of symmetrical A-D-A based systems featuring electron rich EDOT cores and their application as solution processed BHJ solar cells with the acceptor [6,6]-phenyl C 71 -butyric acid methyl ester (PC 71 BM). The molecules were designed to feature EDOT as the central donor moiety with adjacent thiophene p-conjugated units to increase the electron donating ability of the donor component.…”

A–π–D–π–A Electron‐Donating Small Molecules for Solution‐Processed Organic Solar Cells: A Review

“…The same group presented a family of SMs smL02–06 (m116 – m120 ). Various π‐conjugated bridges and end‐capped group 3‐ethylrhodanine were introduced into smL01, and smL06 showed the highest PCE of 4.9% with an outstanding J SC of 12 mA cm −2 owing to the highest IPCE value . To determine the origin of high V OC s of these molecules, Tuladhar et al analyzed the V OC losses using electroluminescence and external quantum efficiency (EQE) measurements and the relationship between light absorption and emission.…”