Modeling electrical characteristics of thin-film field-effect transistors

Study of trap states in zinc oxide (ZnO) thin films for electronic applications

“…This problem is well known and has been addressed in a-Si TFT technology [9] as well as in organic based devices [10,11].…”

“…This behavior occurs when there is a large density of traps compared to the density of free carriers [11]. Particular care is then needed when one has to estimate values for the mobility.…”

“…The lower the oxygen content during deposition, the smaller the current. Furthermore, the curves become clearly supra-linear for small V DS , phenomena often called 'contact effects', however, non-linearities are also readily explained by assuming a Poole and Frenkel field assisted thermal excitation from abundant deep levels [11].…”

Metal–Insulator–Metal Transistors

“…For the 30% covered device, the transfer curves are highly non-linear (/ V 7:6 g ), which indicates that traps play a dominant role [17,18] (traps are not included here in the simplified model). On the other hand, the transfer curve of the 50% covered device is linear, which shows that this device behaves more like an ideal transistor.…”

“…Thus TFTs merit their own modeling. [17] The single postulate needed is effectively treating the device as a parallel-plate capacitor in which the charge density, r(x), at any place x along the channel, is given by the local potential drop across the insulator (here called oxide for historical reasons) multiplied by it's capacitance density (C ox ¼ e ox /d ox , with e ox the permittivity and d ox the thickness of the oxide layer), namely…”