New Compact Modeling Solutions for Organic and Amorphous Oxide TFTs

Abstract

We review recent compact modeling solutions for Organic and Amorphous Oxide TFTs (OTFTs and AOS TFTs, respectively), which were developed, under the framework of the EU-funded project DOMINO, to address issues specifically connected to the physics of these devices. In particular, using different approaches, analytical equations were formulated to model the Density of States (DOS), different transport mechanisms, trapping/de-trapping, drain current, stress, capacitances, frequency dispersion and noise. The final TFT models were, after implementation in Verilog-A, validated by means of the design and simulation of test circuits.

Subgap states in aluminium- and hydrogen-doped zinc-oxide thin-film transistors

“…2(b), (e), and (h), using the Meyer–Neldel rule of I ( V gs ) = I 0 exp(− E a /k b T ). 34,35 By assuming that the deduced gate-dependent activation energy ( E a ) is the energetic difference between the Fermi level of the semiconductor and the conductive states (the conduction band minimum (CBM)), the localized (trap) density of states (DOS) of g ( E ) for the pure and doped ZnO TFTs were extracted using the following relation: 36–38 Next, the extracted localized densities of state profile of the ZnO TFTs was fitted with the Gaussian DOS model to estimate the total concentration of the charge traps and the width of the distributions, which are expressed as follows: 39,40 where σ is the width of the distribution, N is the total concentration of the charge traps, and E c is the position of the center of the peak. Fig.…”

The Schottky barrier transistor in emerging electronic devices

“…Amorphous IGZO TFTs are now able to realize mobilities higher than 10 cm 2 V −1 s −1 , I on /I off ratios higher than 10 7 and SSs close to the ideal value [228][229][230][231][232][233]. performance depends on whether the material is vacuum deposited (average mobilities >20 cm 2 V −1 s −1 ) [234] or solution-based n-type metal-oxide TFTs (average mobilities ≈10 cm 2 V −1 s −1 ) [235].…”

THM-OTFT: A Complete Physics-Based Verilog-A Compact Model for Short-Channel Organic Thin-Film Transistors

“…The DC model in [7] [9] is a charge-based model, which means that the current is calculated based on the charge densities Q ms and Q md on the source and the drain ends of the channel (see Fig. 1).…”

“…The design of complex integrated systems based on organic transistors relies on accurate and efficient compact models for these devices, serving as a bridge between device technology and the circuit level and allowing for efficient circuit simulation. Based on the physics of organic semiconductors (OSC) [4] [5], numerous approaches to compact models for organic TFTs have been proposed [6] [7]. However, some of them are lacking physical insight or do not provide the flexibility required for the model to be readily adapted to different technologies.…”