title: High-performance polymer semiconducting heterostructure devices by nitrene-mediated photocrosslinking of alkyl side chains.
abstract: Heterostructures are central to the efficient manipulation of charge carriers, excitons and photons for high-performance semiconductor devices. Although these can be formed by stepwise evaporation of molecular semiconductors, they are a considerable challenge for polymers owing to re-dissolution of the underlying layers. Here we demonstrate a simple and versatile photocrosslinking methodology based on sterically hindered bis(fluorophenyl azide)s. The photocrosslinking efficiency is high and dominated by alkyl side-chain insertion reactions, which do not degrade semiconductor properties. We demonstrate two new back-infiltrated and contiguous interpenetrating donor-acceptor heterostructures for photovoltaic applications that inherently overcome internal recombination losses by ensuring path continuity to give high carrier-collection efficiency. This provides the appropriate morphology for high-efficiency polymer-based photovoltaics. We also demonstrate photopatternable polymer-based field-effect transistors and light-emitting diodes, and highly efficient separate-confinement-heterostructure light-emitting diodes. These results open the way to the general development of high-performance polymer semiconductor heterostructures that have not previously been thought possible.
authors: Department of Physics, National University of Singapore, Lower Kent Ridge Road, S117542, Singapore.
authors: Rui-Qi
authors: RQ
authors: Png
authors: Perq-Jon
authors: PJ
authors: Chia
authors: Jie-Cong
authors: JC
authors: Tang
authors: Bo
authors: B
authors: Liu
authors: Sankaran
authors: S
authors: Sivaramakrishnan
authors: Mi
authors: M
authors: Zhou
authors: Siong-Hee
authors: SH
authors: Khong
authors: Hardy S O
authors: HS
authors: Chan
authors: Jeremy H
authors: JH
authors: Burroughes
authors: Lay-Lay
authors: LL
authors: Chua
authors: Richard H
authors: RH
authors: Friend
authors: Peter K H
authors: PK
authors: Ho