Dually crosslinkable SiO2@polysiloxane core-shell nanoparticles for flexible gate dielectric insulators

Abstract

A hybrid gate dielectric material for flexible OTFT is developed by using core-shell nanoparticles (SiO2@PSRXL) where the core and the shell consist of silica nanoparticles and polysiloxane resin, respectively. Since polysiloxane resin contains both thermal-and photo-crosslinkable functional groups, densely-crosslinked thin gate dielectric films can be easily prepared on various substrates by conventional solution casting followed by dual crosslinking. SiO2@PSRXL films exhibit high thermal stability (weight loss at 300 degrees C is smaller than 3 wt%). The dielectric films made of SiO2@PSRXL show an exceptionally low leakage current and no breakdown voltage up to 4.3 MV cm(-1), which are comparable to those of silica dielectrics prepared by CVD. OTFT devices based on dibenzothiopheno[6,5-b: 6',5'-f] thieno[3,2-b] thiophene (DTBTT) as a semiconductor and SiO2@PSRXL as a gate dielectric exhibit good hole mobility (2.5 cm(2) V-1 s(-1)) and I-on/I-off ratio (10(6)).