Operational stability of solution based zinc tin oxide/SiO2 thin film transistors under gate bias stress
Applied Physics Letters Vol. 3, Nº 6, pp. 062804 - 062804, April, 2015.
ISSN (print): 1077-3118
ISSN (online): 0003-6951
Scimago Journal Ranking: 1,50 (in 2015)
Digital Object Identifier: 10.1063/1.4919057
his study, we report solution-processed amorphous zinc tin oxide transistors exhibiting high operational stability under positive gate bias stress, translated by a recoverable threshold voltage shift of about 20% of total applied stress voltage. Under vacuum condition, the threshold voltage shift saturates showing that the gate-bias stress is limited by trap exhaustion or balance between trap filling and emptying mechanism. In ambient atmosphere, the threshold voltage shift no longer saturates, stability is degraded and the recovering process is impeded. We suggest that the trapping time during the stress and detrapping time in recovering are affected by oxygen adsorption/desorption processes. The time constants extracted from stretched exponential fitting curves are ≈106 s and 105 s in vacuum and air, respectively.