New Conjugated Polymers Based on Dithieno[2,3‐e:3′,2′‐g]Isoindole‐7,9(8H)‐Dione Derivatives for Applications in Nonfullerene Polymer Solar Cells

Abstract

The fast evolution of the narrow bandgap nonfullerene acceptors requires new conjugated wide bandgap polymers for the use of nonfullerene polymer solar cells (PSCs). Herein, two new wide bandgap A1–D1–A2–D1 conjugated polymers with the same dithieno[2,3‐e:3′,2′‐g]isoindole‐7,9(8H)‐dione (DTID) acceptor (A1) and thiophene donor (D1) and different A2 acceptor units, i.e., benzothiadiazole (BT) and fluorinated benzothiadiazole (f‐BT) denoted as P113 and P114, are designed, and the effect of fluorination of the BT acceptor unit on the photovoltaic properties of PSCs using nonfullerene acceptors is investigated. It is found that the incorporation of fluorine atom into the BT acceptor unit increases the absorption coefficients and the relative dielectric constant. The increase in photoluminescence quenching, reduction in charge recombination loss, and improvement in the charge carrier life are observed for P114. All these factors result in the drastically improved power conversion efficiency of P114:ITIC‐m‐based PSC to 10.42% with a small energy loss of 0.56 eV as compared with the P113 counterpart (8.74% with an energy loss of 0.69 eV) under identical conditions. The low energy loss is beneficial to overcome the trade‐off between open‐circuit voltage and short‐circuit current.

Dithieno[2,3‐e:3′,2′‐g]isoindole‐7,9(8H)‐Dione and Dithieno[3′,2′:5,6;2″,3″:7,8]naphtho[2,3‐d]imidazol‐9(10H)‐One‐Based Wide Bandgap Copolymer for Efficient Polymer Solar Cells

“…In Scheme 1 , the synthesis process to design the copolymers P133 and P135 is shown. The monomers 4,8‐Bis (5‐(2‐ethylhexyl) thiophen‐2‐yl) benzo [1,2‐b:4,5‐b'] thiophene‐2,6 diyl) bis (trilstmethyannane) M1, [ 40 ] 2,5‐dibromo‐8,10‐bis (2‐octyldodecyl) −8 H‐thieno [3′,2′:5.6;2″,3″:7.8] naphtho [2,3‐d] imidazole‐9 (10 H) ‐one M2, [ 41 ] and 2,5‐Dibromo‐8‐(2‐octyldodecyl)−7 H‐dithieno [2,3‐e:3′, 2′‐g] isoindole‐7, 9 (8H)‐dione M3 [ 42 ] were synthesized as reported in the literature. The P133 and P135 were prepared by conventional Stille cross‐coupling polymerization among M1 and M2 , or M3 , respectively, in the presence of a palladium catalyst Pd (Ph 3 P) 4 in boiling toluene for 48 h in a stream of argon.…”

Machine-learning-guided prediction of photovoltaic performance of non-fullerene organic solar cells using novel molecular and structural descriptors

“…In the last few years, the power conversion efficiency (PCE) of organic solar cells (OSCs) has been triggered mainly due to the development of novel wide-bandgap conjugated polymers and low-bandgap non-fullerene acceptors (NFAs), active layer morphology optimization, device interface engineering and utilization of various novel nanomaterials. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] Several research groups have reported PCEs of more than 19% in single bulk OSCs. [20][21][22][23][24][25][26] Although high-performance devices have been frequently demonstrated, their PCE and open-circuit voltage (V OC ) still lag behind those of other competing technologies such as Si, GaAs, and perovskite solar cells.…”

Ternary Organic Solar Cells: Recent Insight on Structure–Processing–Property–Performance Relationships

“…Recently, some versatile non‐fullerene acceptors (NFAs) have been dedicated to the OSC owing to easy tuning absorption profile, frontier electronic energy levels adjustment, and modulating crystallinity, leading to OSCs with PCE approaching 20%. [ 26,33–39 ]…”

“…Recently, some versatile non-fullerene acceptors (NFAs) have been dedicated to the OSC owing to easy tuning absorption profile, frontier electronic energy levels adjustment, and modulating crystallinity, leading to OSCs with PCE approaching 20%. [26,[33][34][35][36][37][38][39] This observation motivated us to undertake a comprehensive and systematic review to provide an up-to-date account of the research activities in this rapidly growing research field. Our systematic literature review is exhaustive as we cover a large volume of the most recent and relevant literature, from material processing to device performances and stability.…”