Résumé
We analyze the electrical properties of various transistors made with thin films of polycrystalline silicon (Poly-Si TFTs). The results underlie the preponderant role, in the mechanisms of transport of charge and 1/f noise, of the electric discontinuities (barriers of potential) induced by the charged states within the grain boundaries. A comparative study of conduction and low frequency noise versus gate voltage highlights two regimes: one corresponding to thermioionic conduction, and the other to conduction limited by the diffusion to the interfaces.