POS1-0726
Achieving Stable Ambipolar and Unipolar Transport in NDI-DPP-Thiophene Copolymers for Organic Transistors
When and Where
Nov 30, -0001
12:00am - 12:00am
Presenter(s)
Karina Ayu Larasati (Gyeongsang National University)
Co-Author(s)
Abstract
Donor–acceptor (D–A) conjugated copolymers are promising for organic field-effect transistors (OFETs) because of their tunable charge transport. We designed new copolymers combining naphthalenediimide (NDI, strong acceptor), diketopyrrolopyrrole (DPP, weak donor/acceptor), and thiophene (strong donor). By adjusting the NDI:DPP:thiophene ratio, charge polarity was systematically modulated from hole-dominated unipolar to ambipolar and electron-dominated unipolar transport1. At extreme ratios (1:9 and 9:1), minority carriers were strongly suppressed, resulting in nearly ideal unipolar performance. This is attributed to distinct molecular orientations—edge-on for DPP (hole transport) and face-on for NDI (electron transport)—which hinder minority pathways, while small fractions of donor/acceptor units may act as traps. Unlike typical low-band-gap ambipolar polymers, these copolymers maintain excellent stability under repeated bias cycling. Structural and morphological studies (DFT, AFM, GIXRD) confirmed the origins of transport modulation. Furthermore, stable n-channel OFETs were fabricated using non-chlorinated solvents, highlighting their potential for sustainable organic electronics.
