Facile Synthesis of the O-Functionalized Ladder-Type Dipyran Building Block and Its Application in Polymer Solar Cells

Abstract

A new centrosymmetrical dipyran unit (DTDP) is successfully prepared by means of an efficient and universal way, and a series of PDTDP polymers have been prepared so as to assess their potential application in organic photovoltaic. The function of pyran moiety is not merely limited to tune the electron-donating roles and energy levels but it also contributes to solubility improvement. Interestingly, all pyran-based polymers displayed wide absorption ranging from 350 to 780 nm, but varied aggregation phenomena are observed. Furthermore, the quantum chemistry calculations for dimers, morphology study and grazing-incidence wide-angle X-ray scattering analysis for blend films have been utilized to understand the variations at photovoltaic performances. Finally, PDTDP-4 achieved the highest power conversion efficiency of 7.26% ( V = 0.72 V, FF = 0.66, and J = 15.30 mA/cm), demonstrating promising usage for high-efficiency polymer donors in polymer solar cells. In all, not only a promising dipyran building block is provided by this study, more dipyran derivatives and polymers could be prepared via this facile synthetic route.

Realizing n-Type Field-Effect Performance via Introducing Trifluoromethyl Groups into the Donor–Acceptor Copolymer Backbone

“…We further conducted Scherrer analysis of the (100) peak to quantify the coherence length (CL) which is related to the crystalline size by employing the Scherrer equation: CL = 2πK/fwhm, where K = 0.89 is a shape factor and fwhm represents the full width at half-maximum of a diffraction peak. 48,49 The CL values of the pristine thin films of PAIID- Because the CL value is related to the crystalline size and lattice order, a larger LC value suggests fewer grain boundaries and renders better carrier transport. 16 To further gain insight into the surface morphologies of polymer semiconductor thin films, AFM characterizations were performed.…”

“…Moreover, tuning the branching point of alkyl chains is an effective strategy for gradually modulating the π–π distances, and our results substantiate that PAIID-TFBVB-C3 with 4-decyltetradecyl groups shows shorter π–π distances (∼ 3.45 Å) than that of PAIID-TFBVB-C1 with 2-decyltetradecyl groups (∼3.53 Å). We further conducted Scherrer analysis of the (100) peak to quantify the coherence length (CL) which is related to the crystalline size by employing the Scherrer equation: CL = 2π K /fwhm, where K = 0.89 is a shape factor and fwhm represents the full width at half-maximum of a diffraction peak. , The CL values of the pristine thin films of PAIID-TFBVB-C1 , PAIID-TFBVB-C3 , and PAIID-BVB-C3 are 89.3, 87.5, and 152 Å, respectively. The correspondingly increased values of 143, 145, and 186 Å are obtained after thermal annealing treatment.…”

Molecular optimization of incorporating pyran fused acceptor–donor–acceptor type acceptors enables over 15% efficiency in organic solar cells

“…Pyran fused rings have been explored as distinctive blocks to construct a class of highly efficient NFAs. 11,37,46–58 Recently, our group developed an encouraging NFA, FO-2F , 45 featuring an easily synthesized pyran fused ring as the main building kernel. Note that FO-2F -based OSCs have afforded excellent PCEs, rendering them one of the most promising candidates for economically feasible OSC molecules.…”

Photovoltaic Performances of Fused Ring Acceptors with Isomerized Ladder-Type Dipyran Cores

“…Then, some donor polymers comprising asymmetric dibenzopyran (DBP) units are reported by our group so as to improve the material stability . Combining DTP and DBP units, we design a ladder-type dipyran core (DTDP), which comprises a five-membered fused ring skeleton and two pyran units. − The dipyran unit is also used for the construction of NFAs, the oxygen atoms can improve the electron-donating ability of the dipyran core, resulting in small-band-gap acceptors via the enhanced intermolecular charge transfer effect. DTDP-based NFAs give rise to good photovoltaic performances. , The C–O bond can only slightly twist the dipyran skeleton, but close π–π stacking and strong crystallinity are usually maintained for most dipyran-based NFAs.…”