Efficient semi-transparent organic solar cells enabled by a quasi-heterojunction active layer structure

Abstract

A type of ternary ST-OSC based on a PTB7-Th:10%PCDTBT/IEICO-4Cl quasi-heterojunction prepared by sequential processing was fabricated. The prepared ST-OSC achieves a PCE of 6.30% with an AVT of 43.93%, leading to a LUE of 2.77%.

Sequential Deposition of Multicomponent Bulk Heterojunctions Increases Efficiency of Organic Solar Cells

“…[31,32] Apart from adjusting the frontier energy level and expanding absorption, the introduction of a second donor and/or acceptor has been shown to enhance the crystallinity for charge carrier mobilities and lower the miscibility between donor and acceptor materials for a more pronounced vertical phase separation. [22][23][24][25][26][27][28][29][30][31][32] It is important to note that the donor and acceptor layers are processed separately in these D/A-structured LbL-OSCs, the microstructure of underlying polymer donor layer plays a key role in determining the vertical penetration depth of acceptor and the sufficiency of D/A interfaces. [32][33][34][35][36] Polymer donors require a strong self-assembly ability, and the related assembly process must be tightly controlled to form an appropriate fibril mesh and allow the acceptor molecules to penetrate adequately into the interspace of the polymer mesh; thus, forming ideal bicontinuous networks.…”

“…Combining the advantages of a multicomponent strategy and the LbL processing method provides an opportunity to further improve the photovoltaic performance of OSCs. In recent years, several groups have reported on multicomponent LbL-OSCs based on D/A structures, including D/A1:A2, [22][23][24][25][26][27][28][29] D1:D2/A [30] and D1:D2/A1:A2. [31,32] Apart from adjusting the frontier energy level and expanding absorption, the introduction of a second donor and/or acceptor has been shown to enhance the crystallinity for charge carrier mobilities and lower the miscibility between donor and acceptor materials for a more pronounced vertical phase separation.…”

Semi-transparent organic solar cells based on large bandgap star-shaped small molecules as mixed donors with PM6

“…21 Xie et al used the polymer PCDTBT as a host in PTB7-Th:IEICO-4Cl, which can be optimised to a PCE of 6.30% with an AVT of 43.93% in a film of 90 nm thickness. 22 Instead of using wide E g polymers as host or second donors, small molecules can also be used as donors to fabricate OSCs. Even though small molecular donors are rarely reported, some examples can be listed in binary OSCs containing chemical structures such as oligothiophene DRCN7T, 23 and N,N 0 -diaryl-diamines.…”

High-performance semitransparent organic solar cells enabled by pseudo-planar heterojunction structures combined with optical engineering

“…42–44 The active layer with the PPHJ structure can allow for more freedom to modulate the optical and charge transport properties, in which the donor and acceptor layers can be optimized independently and the desired vertical component distribution can be achieved simultaneously. 45 Considering that the donor component absorbs mainly photons of visible light while the acceptor component absorbs strongly at NIR wavelengths, both Huang et al and Wei et al achieved the simultaneously enhanced PCE and AVT using the PPHJ strategy in comparison with the BHJ, by simply adjusting the thickness of the acceptor layer or the donor layer while fixing the other layer. 46,47 Furthermore, compared with the BHJ structure, the PPHJ structure is beneficial for the reduction of the optical loss and conducive to printing.…”