Cellulose nanocomposite as an effective substrate for OLEDs

Abstract

Nanocomposite film composed of bacterial cellulose (10-50 wt%) and polyurethane (PU) based resin was fabricated and utilized as a substrate for flexible organic light emitting diode (OLED) display. The performance of the nanocomposite satisfied the criteria for the substrate of OLED with an additional featur of flexibility. The visible light transmittance of the nanocomposite film was as high as 80%. Its thermal stability was stable up to 150C while its dimensional stability in terms of coefficient of thermal expansion (CTE) was less than 20 ppm/K. Moreover, Si-O film and ferrofluid solution were employed to protect anaocomposite substrate from moisture and to reduce the surface roughness, respectively. Water vapor transmission rate (WVTR) and surface roughness must be lower than 10-6 g/m2/day and 5 nm, respectively. Consequently, in order to fabricate OLED circuit, we investigated PEDOT: PSS, silver nanoparticle and ZnS nanoparticle were investigated for being as anode, cathode and emissive layer, respectively. The use of desktop inkijet printer was empolyed to use employed to use as instrument in order to deposit OLED layer