Analytical model for donor like Gaussian traps in organic thin-film transistor

Abstract

Structural defects and chemical impurities exist in organic semiconductors acting as trap centers for the excited states. This work presents a novel analytical model to calculate the trapping and detrapping rates between two Gaussian densities of states. Miller-Abrahams rate and Fermi-Dirac statistics are employed in this model. The introduction of effective filled and empty sites for correlated bands greatly simplifies the expression of recombination rate. A technology computer-aided design simulator was used to simulate the donor-like traps in an organic semiconductor DPP-DTT based thin-film transistor, showing excellent agreement with the measured subthreshold swing difference and residual surface charge in the transfer characteristics. • A new method to analyze the trapped charges between two Gaussian density of states in organic semiconductors. • Two variables are defined in the expression of detrapping rate to simplify the algorithm complexity. • This approach can be conveniently applied on the technology computer-aided design (TCAD) technology. • A good agreement with the measured transfer characteristic confirms the robustness of this approach.