Universal three-dimensional crosslinker for all-photopatterned electronics

Min Je Kim,Hyukmin Kweon,Jeong Ho Cho,Seunghan Kim,Bongsoo Kim,Jong-Ho Choi,Do Hwan Kim,Jeehye Yang,Myeongjae Lee,Honggi Min,Du Yeol Ryu,Moon Sung Kang,Wooseop Lee

doi:10.1038/s41467-020-15181-4

Abstract

All-solution processing of large-area organic electronics requires multiple steps of patterning and stacking of various device components. Here, we report the fabrication of highly integrated arrays of polymer thin-film transistors and logic gates entirely through a series of solution processes. The fabrication is done using a three-dimensional crosslinker in tetrahedral geometry containing four photocrosslinkable azide moieties, referred to as 4Bx. 4Bx can be mixed with a variety of solution-processable electronic materials (polymer semiconductors, polymer insulators, and metal nanoparticles) and generate crosslinked network under exposure to UV. Fully crosslinked network film can be formed even at an unprecedentedly small loading, which enables preserving the inherent electrical and structural characteristics of host material. Because the crosslinked electronic component layers are strongly resistant to chemical solvents, micropatterning the layers at high resolution as well as stacking the layers on top of each other by series of solution processing steps is possible.

Highlights

All-solution processing of large-area organic electronics requires multiple steps of patterning and stacking of various device components
Polystyrene (PS) and poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) can be used for the gate dielectric material. Each of these device component layers was photopatterned using a blend solution of the corresponding electronic material and the (2,2-bis(((4-azido2,3,5,6-tetrafluorobenzoyl)oxy)methyl)propane-1,3-diyl bis(4azido-2,3,5,6-tetrafluorobenzoate), i.e., 4Bx. 4Bx is structured in three-dimensional tetrahedral geometry containing four photocrosslinkable azide moieties each at the four corners of the molecule
Because photocrosslinking reaction can undergo with materials containing alkyl groups, i.e., C–H bonds, 4Bx can be universally applicable to a variety of electronic materials that are processable with common organic solvents; the electronic materials include polymer semiconductors, polymeric gate dielectrics, and even conductive metal NPs bearing organic surfactants

Summary

Introduction

All-solution processing of large-area organic electronics requires multiple steps of patterning and stacking of various device components. The performance of electronic devices based on various solution-processable materials, such as polymer semiconductors, organic small molecules, and nanostructured materials, is being improved continually[6,9,10,11,12,13,14,15] Fabrication of these devices entirely through a series of solution processes remains highly challenging, as they comprise a stack of fully patterned electronic components, such as electrode layers, charge transporting interlayers, active channel layers, and insulating layers. Inkjet printing and nanoimprinting methods face several difficulties in producing uniform and large-area electronic devices on a large scale[21,22,23,24,25,26] They suffer from the same drawbacks of the solution-processed materials arising from their poor chemical robustness; the prepatterned underlayer is susceptible to the solution-based deposition process of the layer above it. We demonstrate the fabrication of NOT, NAND, and NOR logic gates based on arrays of all-photopatterned p-type and n-type PTFTs

Methods

Results

Conclusion