Effects of humidity on unencapsulated poly(thiophene) thin film transistors
The effects of humidity on unencapsulated polymeric thin-film transistors (TFTs) were investigated. TFTs were fabricated on glass substrates with inorganic gate dielectric and a semiconducting layer of poly[5,5'-bis(3-dodecyl-2-thienyl)-2,2'-bithiophene], PQT-12. The field effect mobility of PQT-12 TFTs decreases and the rate of trapping of charge carriers increases under increasing humidity. The amount of water absorbed by the PQT-12 films was measured using a quartz crystal microbalance. Thin films of PQT-12 absorb comparable amounts of water to the carrier concentration in TFTs under routine operating conditions (humidity of 30% R.H. and gate voltage of -30 V); the changes in electrical characteristics under humid atmospheres are attributed to the interaction of absorbed water with the carriers in the film.
Chabinyc, M. ; Endicott, F .; Vogt, B. D.; Delongchamp, D.; Lin, E. K.; Wu, Y.; Liu, P.; Ong, B. S. Effects of humidity on unencapsulated poly(thiophene) thin film transistors. Applied Physics Letters. 2006 March 13; 88 (11): 113514-1-3.