Panchromatic Ternary Organic Solar Cells with Porphyrin Dimers and Absorption-Complementary Benzodithiophene-based Small Molecules

Abstract

Diketopyrrolopyrrole–ethynylene-bridged porphyrin dimers are capped with electron-deficient 3-ethylrhodanine (A2) via a π-bridge of phenylene ethynylene, affording two new acceptor–donor–acceptor structural porphyrin dimers (DPP-2TTP and DPP-2TP) with strong absorption in ranges of 400–550 nm (Soret bands) and 700–900 nm (Q bands). Their intrinsic absorption deficiency between the Soret and Q bands could be perfectly compensated by a wide-bandgap small molecule DR3TBDTTF (D*) with absorption at 500–700 nm. Impressively, the optimal ternary device based on the blend films of DPP-2TPP, DR3TBDTTF (20 wt %), and PC71BM shows a PCE of 11.15%, whereas the binary devices based on DPP-2TTP/PC71BM and DPP-2TP/PC71BM blend films exhibit PCEs of 9.30 and 8.23%, respectively. The high compatibility of the low bandgap porphyrin dimers with the wide-bandgap small molecule provides a new threesome with PC71BM for highly efficient panchromatic ternary organic solar cells.

15.3% efficiency all-small-molecule organic solar cells enabled by symmetric phenyl substitution

“…Compared with polymer-based OSC, NFSM-OSC is more suitable as a research model device, which can more easily establish clear relationships between the structure and performance [4][5][6][7][8]. However, the power conversion efficiencies (PCEs) of current state-of-the-art NFSM-OSCs are still much lower than that of polymer-based OSCs because small molecules cannot form pre-aggregation in solution like most high-performance polymers [9-11], and have similar acceptor-donor-acceptor (A-D-A) skeleton structures with high efficiency non-fullerene acceptors, making it difficult to regulate their morphology [12][13][14][15][16][17][18][19][20][21]. To date, though considerable efforts have been made in the research of NF acceptors and a number of high-performing materials have been reported, the study on small molecule donors for efficient NFSM-OSCs is relatively lagging [1, [22][23][24][25][26].…”

Diketopyrrolopyrrole linked porphyrin dimers for visible-near-infrared photoresponsive nonfullerene organic solar cells

“…40,41 Over the past several years, we and other groups have steadily worked for the development of porphyrin SM electron donors in OSCs due to their excellent super p-conjugation properties, tremendous light-harvesting capabilities, exceptional charge transport mobilities, and easy processability with fullerene acceptors, as a result, achieving high PCEs up to 10%. [42][43][44][45][46][47][48][49][50][51][52][53][54][55] One major disadvantage of porphyrin derivatives for OSCs is that they usually show a deep valley between the intense Soret band (400-500 nm) and Q-bands (650-800 nm). 45,56 It is still challenging to design a porphyrin molecule with a full spectrum from 300 nm to 900 nm.…”

“…[42][43][44][45][46][47][48][49][50][51][52][53][54][55] One major disadvantage of porphyrin derivatives for OSCs is that they usually show a deep valley between the intense Soret band (400-500 nm) and Q-bands (650-800 nm). 45,56 It is still challenging to design a porphyrin molecule with a full spectrum from 300 nm to 900 nm. Recently, ternary OSCs were proposed to be used as the third component as an absorption complementary donor or acceptor to achieve a full absorption spectrum.…”

“…Impressively, the photon-current conversion of the device crossed over UV-visible and NIR regions, and as a result, a PCE of 11% was recorded. 45 At the same time, Jang et al, 60 Jen et al, 29 and Wan et al 61 have succeeded without using a third component to construct a binary layer system of porphyrin donors and NF acceptors for all SM-OSCs. However, only a very few binary layer systems featuring porphyrin donors and NFSM acceptors have been reported so far for OSCs.…”

Improving the efficiencies of small molecule solar cells by solvent vapor annealing to enhance J-aggregation

“…[26][27][28] And the expanded and enhanced absorptions in J-aggregation-based films provide the potential chance to fabricate broader light response and larger short-circuit current (J SC ) solar cell devices. Some of porphyrin derivatives are near-infrared (NIR) organic semiconductors with optical bandgap less than 1.5 eV which have attracted much attention due to their great contribution to the field of NIR photodetector, 29,30 SM-OSCs, [31][32][33][34][35][36][37][38][39][40][41] ternary solar cells [42][43][44][45][46] and tandem solar cells. 47,48 In this contribution, we report dimer porphyrin molecule ZnP2-DPP 49 (Figure 1 .…”