A new polymer acceptor containing naphthalene diimide and 1,3,4‐thiadiazole for all‐polymer solar cells

Abstract

A n‐type conjugated polymer containing naphthalene diimide (NDI) and 1,3,4‐thiadiazole (TZ) moieties, named PNTZ, has been synthesized and applied for all‐polymer solar cells (all‐PSCs). By the incorporation of TZ unit into the polymer main chains, the lowest unoccupied molecular orbital level of this polymer has been adjusted effectively. In addition, the electron‐acceptor PNTZ shows a broad absorption spectrum in the range of 300–700 nm, and possesses complementary absorption spectrum with the electron‐donor PTB7‐Th. On the basis of PNTZ as the acceptor and PTB7‐Th as the donor, the all‐PSCs are fabricated. After optimization, the well blend morphologies with a continuous D/A interpenetrating network are observed and the best all‐PSC device exhibits a power conversion efficiency of 4.35% with a high short‐circuit current density of 13.26 mA cm−2. This research demonstrates that the TZ‐containing polymer PNTZ is a promising non‐fullerene acceptor for high efficiency all‐PSCs. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2017, 55, 990–996

Recent Advances, Design Guidelines, and Prospects of All-Polymer Solar Cells

“…Since there are many NDI-based P A s that have been assessed in all-PSCs, we do not discuss all the results, which are well-documented in other recent reviews. − Rather, in this section, we focus on some NDI-based P A s that have produced important advances in all-PSC performance and present guidelines for the design of P A s suitable for high-performance all-PSCs (Table ). ,,,− ​ Our discussion starts from the observation that P­(NDI2OD-T2) is still one of the best-performing P A s in all-PSCs. In most cases where the molecular structures of NDI-based P A s are largely modified from the P­(NDI2OD-T2), we noted that the PCEs of the corresponding all-PSCs generally decreased. ,− ,− For example, successful NDI-based P A s have rarely been reported in which the bithiophene (T2) units in P­(NDI2OD-T2) were replaced by bulkier electron-donating units.…”

Realizing Over 13% Efficiency in Green‐Solvent‐Processed Nonfullerene Organic Solar Cells Enabled by 1,3,4‐Thiadiazole‐Based Wide‐Bandgap Copolymers

“…TDZ cycle is highly polarizable with a large electron affinity, which can be used as an excellent electron acceptor block for constructing high‐performance D–A copolymers in the OSCs. However, TDZ‐based copolymer donors received less attention and showed unsatisfactory device performances . On the other hand, BDT unit features a weak electron‐donating property, which is a good candidate as the donor block for building wide‐bandgap copolymers.…”

Modulating the Symmetry of Benzodithiophene by Molecular Tailoring for the Application in Naphthalene Diimide‐Based N‐Type Photovoltaic Polymers

“…Aiming at the improvement in the photovoltaic properties from N2200, a large number of novel NDI‐based polymers are designed and synthesized by changing the copolymerized units as summarized in Figure . A great deal of electron‐donating units such as thiophenes (T), selenophene (Se), tellurophene (Te), difluorobithiophene (2fT), thienylene−vinylene−thienylene (TVT), furanylene‐vinylenefuranylene (FVF),selenoloselenophene (SS), diselenophene (Se2), thienothiophene (TT),thienodithiophene (DTT), trithiophene (3T), dithienylene‐thienothiophene (DT‐TT), dithienylene‐thienodithiophene (DT‐DTT), dithienylene‐diketopyrrolopyrrole (DT‐DPP), dithienylene‐thiadiazole (DT‐TZ), dithienylene‐oxadiazole (DT‐OZ), thienylene‐difluorophenylene‐thienylene (TffPT), fluorene (F), carbozole (C), cyclopentadithiophene (CPDT), dithienosilole (DTS), benzodithiophene (BDT), indacenodithiophene (IDT), triphenylamine (TPA), etc. have been utilized to modulate the properties of final NDI‐based polymers.…”