Efficient N-Type Organic Electrochemical Transistors and Field-Effect Transistors Based on PNDI-Copolymers Bearing Fluorinated Selenophene-Vinylene-Selenophenes

n-Type organic electrochemical transistors (OECTs) and organic field-effect transistors (OFETs) are less developed than their p-type counterparts. Herein, polynaphthalenediimide (PNDI)-based copolymers bearing novel fluorinated selenophene-vinylene-selenophene (FSVS) units as efficient materials for both n-type OECTs and n-type OFETs is reported. The PNDI polymers with oligo(ethylene glycol) (EG7) side chains P(NDIEG7-FSVS), afford a high & mu;C* of > 0.2 F cm-1V-1s-1, outperforming the benchmark n-type Pg4NDI-T2 and Pg4NDI-gT2 by two orders of magnitude. The deep-lying LUMO of -4.63 eV endows P(NDIEG7-FSVS) with an ultra-low threshold voltage of 0.16 V. Moreover, the conjugated polymer with octyldodecyl (OD) side chains P(NDIOD-FSVS) exhibits a surprisingly low energetic disorder with an Urbach energy of 36 meV and an ultra-low activation energy of 39 meV, resulting in high electron mobility of up to 0.32 cm(2) V-1 s(-1) in n-type OFETs. These results demonstrate the great potential for simultaneously achieving a lower LUMO and a tighter intermolecular packing for the next-generation efficient n-type organic electronics.

Automated summary

Reported is the use of polynaphthalenediimide (PNDI)-based copolymers containing novel fluorinated selenophene-vinylene-selenophene (FSVS) units as efficient materials for n-type organic electrochemical transistors (OECTs) and organic field-effect transistors (OFETs). The PNDI polymers with oligo(ethylene glycol) (EG7) side chains P(NDIEG7-FSVS) achieved a high carrier mobility of > 0.2 F cm-1 V-1s-1, outperforming benchmark materials by two orders of magnitude. The conjugated polymer with octyldodecyl (OD) side chains P(NDIOD-FSVS) exhibited low energetic disorder and ultra-low activation energy, resulting in high electron mobility in n-type OFETs.