Two Birds with One Stone: High Efficiency and Low Synthetic Cost for Benzotriazole‐Based Polymer Solar Cells by a Simple Chemical Approach

Abstract

layer materials, device structures, and the interfacial engineering. [3-9] Especially beneficial from the concept of bulk heterojunction (BHJ) in photoactive materials consisting of donor and acceptor, the power conversion efficiency (PCE) of OPV cells has approached about 15∼17% for single junction and tandem devices, respectively. [10-18] Currently, for material and chemistry researchers, most works have been focused on the design of molecular structures of the polymer donor and the small molecular acceptor because undoubtedly they show most contributions to the device efficiency and its final cost. [19-27] Therefore, the simplification of synthetic routes of high-performance polymer donor is required for industrial scale production of OPV technology. Poly(3-hexylthiophene-2,5-diyl) (P3HT) is a good polymer donor candidate for low-cost modules fabrications. However, its inferior PCE limits its potential application value. [28,29] In the meantime, the reported polymers with high PCEs over 14% are all based on benzodithiophene (BDT) containing building block. [10,30-34] The advantages of high planar structure and extended Π-conjugated degree of BDT unit exhibit its merits in high charge mobility and high PCE. [35-37] Specially, the fluorination of conjugated side chains on BDT based polymer cause closer interchains interactions and more crystalline properties and subsequently high mobility and PCE. [22,38] However, just like a coin has its two sides, the complicated synthetic routes and high material cost of the fluorination of BDT-based polymer hamper the widespread commercial application of OPVs. [39] In considering the importance of polymer materials and the urgency of OPVs commercialization, a satisfaction in efficiency and cost is becoming a tremendous challenge for polymeric structure design. In previous works, most of them focus on designing and synthesizing highly efficient photovoltaic polymer donor without further considering synthetic cost. Chen and Brabec et al. independently have comments on the importance on low cost and high efficiency. [40,41] Currently, only a few groups have realized the problem and have developed some more convenient synthetic strategies to fulfill the target polymer with cost efficiency and high performance. For example, Hou et al. developed a chlorination of conjugated side Low synthetic cost and high performance are becoming a new challenge in designing polymer donors for large-scaled polymer solar cells (PSCs) fabrication; however, complicated synthetic routes and high material costs hamper the widespread commercial application of OPVs. Here, a simple and low-cost chemical steric effect (SE) is introduced to BDT-based side chains. Through adjusting alkyl side chains, the polymeric crystallinity and miscibility are rebalanced and subsequently the photovoltaic device based on the metapositioned alkyl polymer outperforms its para-positioned counterpart. The champion device based on the polymer with the meta-positioned side chains affords a PCE of 14.53% without sacrificing its...

Simulation of Charge Carriers in Organic Electronic Devices: Methods with their Fundamentals and Applications

“…The Equations ( 25),( 26),( 29), (30), and (33) form a system of equations the solution of which yields the current densities j n , j p and the charge carrier densities n, p. At this stage, the material-specific properties of our device have already entered the model via the effective material parameters ( ) r r ε , μ n/p , and D n/p in Equations (29,30,33). Due to the spatial dependence of the material parameters and (intentionally introduced) doping densities, also layer sequences and thicknesses are passed to the model.…”

Recent Advances of Furan and Its Derivatives Based Semiconductor Materials for Organic Photovoltaics

“…[ 22–27 ] From initial poly(3‐hexylthiophene) (P3HT) to current famous benzo[1,2‐b:4,5‐b']dithiophene (BDT)‐based PM6, the PCE of OSCs‐based thiophene and its derivatives have risen from less 6% to over 17%. [ 28–36 ]…”

High‐Efficiency Organic Solar Cells Based on Asymmetric Acceptors Bearing One 3D Shape‐Persistent Terminal Group

“…PBDB-T, a more cost-effective polymer than PM6 for realistic application, was selected as the donor to pair with these six NFAs. [39][40][41][42][43][44] The chemical structures of the two polymers are shown in Figure S1 (Supporting Information). Compared with symmetric NFAs based blend films, asymmetric NFAs based ones exhibit better nanoscale phase separation, higher crystallinity, larger and more balanced charge carrier mobilities, and higher fill factor (FF).…”