POS5-0767
Conjugated Polymer Network Nanoparticles as Stable Photoactive Layers for Organic Photodetectors
When and Where
Nov 30, -0001
00:00 - 00:00
Presenter(s)
Choi minjun (Daegu Gyeongbuk Institute of Science and Technology (DGIST))
Co-Author(s)
Abstract
Covalent organic frameworks (COFs) are emerging as promising organic semiconducting materials for photodetector applications owing to their extended π-conjugation and tunable optical properties. However, highly crystalline vinylene-linked COFs suffer from short interlayer distances and regular π-stacking, which can induce [2+2] photocycloaddition under light irradiation, disrupting framework conjugation and reducing photoresponse stability.
Amorphous TPA-COFs, in which the bulky triphenylamine (TPA) core suppresses ordered interlayer stacking, offer an alternative route to mitigate this photochemical side reaction and improve operational stability. However, bulk COFs present poor film-forming ability, limiting their direct application as uniform photoactive layers.
To address this, a poly(N,N-dimethylacrylamide) (PDMA) polymer dispersant was introduced to control the growth of COF particles, yielding TPA-COF nanoparticles of approximately 200 nm and 80 nm. The improved dispersibility of the nanoparticles enabled uniform film coating with reduced pinhole formation, aggregation, and surface roughness. Photodetector devices incorporating the TPA-COF nanoparticle layers exhibited enhanced photocurrent, on/off ratio, responsivity, detectivity, and photoresponse stability compared to bulk COF-based devices.
Amorphous TPA-COFs, in which the bulky triphenylamine (TPA) core suppresses ordered interlayer stacking, offer an alternative route to mitigate this photochemical side reaction and improve operational stability. However, bulk COFs present poor film-forming ability, limiting their direct application as uniform photoactive layers.
To address this, a poly(N,N-dimethylacrylamide) (PDMA) polymer dispersant was introduced to control the growth of COF particles, yielding TPA-COF nanoparticles of approximately 200 nm and 80 nm. The improved dispersibility of the nanoparticles enabled uniform film coating with reduced pinhole formation, aggregation, and surface roughness. Photodetector devices incorporating the TPA-COF nanoparticle layers exhibited enhanced photocurrent, on/off ratio, responsivity, detectivity, and photoresponse stability compared to bulk COF-based devices.
