A Surface Potential Based Organic Thin-Film Transistor Model for Circuit Simulation Verified With DNTT High Performance Test Devices

Abstract

A compact surface potential based model for organic thin-film transistors (OTFTs), including both tail and deep trap states across the band gap, is reported. The model has been developed on the basis of a complete surface potential approach for undoped-body OTFTs. Accurate surface potentials are calculated by explicitly including the floating backside potential that varies with applied biases. A pseudo-2D resistor model is developed to capture the structural features of the OTFT. The resistor model considers, in particular, the effects originating from a bias dependent 2D current flow in the channel region and results in accurate reproduction of the electrical characteristics. The fitting capability of the developed OTFT model is verified against measured high-performance dinaphtho thieno thiophene (DNTT) based field-effect transistor data. Accurate reproduction of the current characteristics of the OTFT test structures is verified from a week to a strong inversion regime.

Organic thin-film transistor compact model with accurate charge carrier mobility

“…(12)) model parameters as observed in Fig.7 (b). We developed a surface potential model equation with the inclusion of trap charge densities [11], drain current (I ds ) equation as the function of surface potential and backside potential [12][13][14][15], and the resistance model [12]- [13]. We verified the effect of mobility on I ds as shown in Fig.8 (a).…”

OTFTs compact models: analysis, comparison, and insights

“…In this model, a physical compact charge carrier mobility model for OTFTs based on an analysis of the bias-dependent Fermi-energy movement in the band gap is reported. Carrier transport through localised trap states in the band gap is described by a hopping mobility model as a function of surface potential, and the band-like carrier transport in extended energy states is modelled by the PF field-effect mechanism [44][45][46]. The previously reported models did not take into consideration the carrier transport in the band gap of OSCs.…”

“…A mobility expression, which depends on gate voltage, is empirically deduced from a numerical estimation of the simultaneous change in the barrier height, free carrier density, and trapped carrier density [41][42][43]. A physical compact charge carrier mobility model for OTFTs relied on the bias-dependent Fermienergy movement in the band gap is developed by Maiti et al [44]; they utilised hopping mobility model as a function of surface potential to reproduce the carrier transport through localised trap states located in the band gap and the Poole-Frenkel (PF) field-effect mechanism to characterise the band-like carrier transport mechanism in extended energy states [45,46]. The universal OTFT (UOTFT) model, applied in Silvaco SmartSpice, is an OTFT compact model that extends the power mobility law from the percolation theory for VRH carrier transport, to the subthreshold operation region [47][48][49].…”

Evolutionary Computation for Parameter Extraction of Organic Thin-Film Transistors Using Newly Synthesized Liquid Crystalline Nickel Phthalocyanine

“…In this sense, recent advances were made to improve detrimental effects such as poor mobility [12,13,14,15], high process variability [16], non-flexible electrodes [17] or parasitic contact effects [18,19,20,21]. In parallel, many groups have been working in order to develop a universal compact model for OTFTs that incorporates the limitations and physical peculiarities of organic semiconductors [22,23,24,25,26,27,28,29,30,31,32,33,34]. Analyses of the features of different compact models were recently reviewed [35,36].…”