A record breaking PCE of 12.1% is achieved by incorporating 25 wt% of DR3TSBDT into a PTB7-Th:PC71BM host matrix.

A highly flexible and durable transparent graphene electrode with thermal stability was developed via the direct integration of polyimide (PI) on graphene. Due to the high transparency of PI-integrated graphene electrode and intimate contact between graphene and PI substrate, high-efficiency flexible organic solar cell with a PCE of 15.2% and outstanding mechanical robustness was obtained.

1wileyonlinelibrary.com more than 1 cm 2 V −1 s −1 . [ 1,2 ] Furthermore, several recent papers have reported that mobility values surpassing 3 cm 2 V −1 s −1 can be obtained in state-of-the-art donoracceptor (D-A) polymers based on diketopyrrolopyrrole (DPP). The DPP motif not only contributes to tight π−π spacing but also enhances the charge delocalization through its high level of co-planarity and quinoidal structure, being highly benefi cial to charge-carrier transport through intermolecular hopping. [ 2a , 3 ] Even though their stability in ambient electrochemical oxidative processes is necessary for the broadbased, high-value applications mentioned above, solution-processable polymeric semiconductors performing beyond the current levels-reliably exceeding 10 cm 2 V −1 swith an on/off ratio ( I on / I off ) of at least 10 6 -are the most compelling requirement for the progress of organic electronics.Recently, we and other groups suggested the effectiveness of controlling the branching point of the side chain from the polymer backbone for tuning intermolecular self-assembly and charge-carrier mobility. [ 3a-c,4 ] Therefore, side-chain engineering can be as important as manipulating the conjugated building blocks in the backbones when designing high-performance conjugated polymers. [ 5 ] In this work, we report the substantially enhanced charge-transport characteristics of a series of DPP-based polymers showing vastly superior FET performance (hole mobilities ( µ h ) of 12.25 cm 2 V −1 s −1 and I on / I off ≥ 10 6 together with electron mobilities ( µ e ) larger than 2 cm 2 V −1 s −1 ). These have been achieved by simply modulating the side-chain branching position (i.e., replacing the commonly used 2-octyldodecyl solubilizing group as the β -branched chain of the DPPbased polymers with the 5-octylpentadecyl chain ( ε -branched chain)). We also demonstrate the structure−property relationships regarding the interplay of the molecular packing and macroscopic charge-transport effi cacy. Results and Discussion Synthesis and CharacterizationBriefl y, 5-octyl-1-pentadecyliodide as the key ε -branched side chain ( ε -C 8 C 15 ) was obtained from commercially available ) with an on/off ratio ( I on / I off ) of at least 10 6 are achieved in the FETs fabricated using the polymers. The developed polymers exhibit extraordinarily high electrical performance with both hole and electron mobilities superior to that of unipolar amorphous silicon.

No abstract

Considering their superior charge-transfer characteristics, easy tenability of energy levels, and low production cost, organic semiconductors are ideal for photoelectrochemical (PEC) hydrogen production. However, organic-semiconductor-based photoelectrodes have not been extensively explored for PEC water-splitting because of their low stability in water. Herein, we report high-performance and stable organic-semiconductors photoanodes consisting of p-type polymers and n-type non-fullerene materials, which is passivated using nickel foils, GaIn eutectic, and layered double hydroxides as model materials. We achieve a photocurrent density of 15.1 mA cm−2 at 1.23 V vs. reversible hydrogen electrode (RHE) with an onset potential of 0.55 V vs. RHE and a record high half-cell solar-to-hydrogen conversion efficiency of 4.33% under AM 1.5 G solar simulated light. After conducting the stability test at 1.3 V vs. RHE for 10 h, 90% of the initial photocurrent density are retained, whereas the photoactive layer without passivation lost its activity within a few minutes.