Flash light sintering of silver ink for inkjet printed organic thin film transistor on flexible substrate

Abstract

In this paper, flash light sintering of inkjet printed silver tracks using pulsed ultra violet light, has been investigated. This method considerably reduced processing time and did not raise substrate temperature to high value which in turn allowed us to fabricate flexible electronic devices. Here, silver patterns were obtained by inkjet printing of commercially available silver nanoparticle ink on flexible polymeric substrate. The printed ink was then sintered at room temperature and under ambient conditions by flash light irradiation from a xenon lamp using an in-house flash light sintering system. Several sintering parameters were carefully optimized to achieve high electrical conductivity. Finally, feasibility of electronic device application was confirmed by successful fabrication of flexible organic thin film transistor using such silver tracks as source and drain contacts. For device fabrication polystyrene and pentacene were used as gate dielectric and as channel material respectively. Transistor with channel length 28 μm and width 68 μm showed field effect mobility of 0.1 cm2V−1S−1 and ON/OFF ratio of 105.