Low temperature flash light curing of spray coated zirconium oxide gate dielectric for flexible, fully patterned and low voltage operated organic thin film transistor

ABSTRACTIn this work, we present low temperature flash light based curing of spray coated high-k zirconium oxide (ZrOx) thin film to realize low voltage operated flexible and fully patterned organic thin film transistors (OTFTs). A simple sol-gel technique was followed to prepare ZrOx from a zirconium complex. By spraying the precursor solution onto substrate through shadow mask, a patterned film was obtained. On the other hand subsequent flash light curing of the coated film not only reduced processing time but also allowed us to fabricate device on polymeric flexible substrate. Spectroscopic analysis confirmed formation of ZrOx film from the solution of zirconium complex. Finally as prepared ZrOx was used as gate dielectric layer in OTFT structure to keep operating voltage as low as -3V. Flexible polyethylenetrephthalate (PET) sheet was used as flexible substrate and pentacene was used as organic active layer. Each and every layer was deposited through metal made shadow mask to develop fully patterned OTFT. Field effect mobility and ON/OFF ratio of as fabricated transistor was found to be as high as 1.2 cm2V-1S-1 and 105 respectively.