Acceptor–donor–acceptor type molecules for high performance organic photovoltaics – chemistry and mechanism

Abstract

The chemical structure–property relationships and mechanism for high performance organic photovoltaics of acceptor–donor–acceptor type molecules are discussed.

High‐Efficiency Ternary Organic Solar Cells Based on the Synergized Polymeric and Small‐Molecule Donors

“…Bulk heterojunction (BHJ) organic solar cells (OSCs) are on the path to becoming an integral part of renewable energy source. [1][2][3][4][5] Especially, the power conversion efficiencies (PCEs) of OSCs have been drastically improved in recent years due to the rapid progresses of nonfullerene acceptors (NFAs) [6][7][8][9][10][11][12][13][14][15][16] as well as the related devices. [17][18][19][20][21] Though promising, significant challenges remain for further performance enhancement of OSCs due to the presence of trade-off between photovoltage and photocurrent of devices.…”

Intrinsically Chemo- and Thermostable Electron Acceptors for Efficient Organic Solar Cells

“…With the development of non-fullerene acceptors (NFAs), organic solar cells (OSCs) have rapidly reached over 17 % power conversion efficiency (PCE) in recent years. [1][2][3][4][5] Though promising for the tunable optoelectronic properties of acceptor-donor-acceptor (A-D-A) NFAs, [6][7][8][9][10][11][12][13] it is worth noting that their synthetic strategy exclusively employs the condensation of aldehyde and active methylene through Knoevenagel condensation reaction (KCR), [14][15][16][17][18][19] leaving a vulnerable exocyclic vinyl group between the donor core and terminal acceptor group in A-D-A NFAs. [20][21][22][23][24] These structural factors potentially undermine the intrinsic chemo-and photostability of NFAs, [25][26] wherein oxygen and water can attack the vulnerable exocyclic vinyl groups between D and A units, hence accelerating the degradation of photoexcited acceptors.…”

Effect of main and side chain chlorination on the photovoltaic properties of benzodithiophene-alt-benzotriazole polymers

“…[1][2][3] Coupled with its low cost, lightweight, promise for flexible roll-to-roll processing, and semi-transparent characteristics, 4 the gap to successful commercialization is decreasing. [5][6][7] The breakthrough in efficiency was mainly due to the discovery and development of new non-fullerene acceptors (NFAs) in the active layer, 8,9 such as ITIC 10 and Y6 and their derivatives. 11 Meanwhile, the donor materials that match the acceptors in the photoactive blend, play an equally important role.…”