Preparation and characterization of ITO, NPB and Alq3 thin films on transparent clay substrate for flexible OLED applications

Transparent flexible freestanding polymer doped clay (TPP-LiSA) films were prepared. The DTA curve of polymer doped clay showed an exothermic peak at the range of 260-315°C. Nanocrystalline ITO thin films were prepared on flexible clay substrate by ion beam sputtering method. The average optical transparency of ITO/clay is estimated as 70 %. NPB and Alq3 thin films were prepared on ITO/clay by vacuum evaporation method. The PL spectra of NPB and Alq3 thin films showed emission peaks at 435 and 540 nm, respectively. The J-V characteristics of Ag/NPB/ITO/Clay and Ag/Alq3/ITO/Clay showed the Ohmic behaviour. The J-V characteristic of Ag/Alq3/NPB/ITO/Clay showed nonlinear Schottky behaviour.