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A comprehensive density-of-states model for oxide semiconductor thin film transistors

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Abstract

In this paper, a novel and comprehensive density-of-states model is presented to understand the origin of conductivity and the performance of p-type and n-type oxide semiconductor thin film transistors (TFTs). To validate the model, the simulated I–V characteristics are compared with measured results of p-type Cu2O and SnO and n-type SnO2 TFTs. It was observed that cation vacancies are responsible for hole conduction in p-type TFTs, while anion vacancies and/or metal interstitials are responsible for electron conduction in n-type TFTs. This was observed by assigning the cation vacancies to acceptor-like Gaussian states and anion vacancies and/or metal interstitials to donor-like Gaussian states. The characteristic slopes in conduction/valence band-tail states are due to disorders present in the oxide semiconductors. The model successfully delivers the physical insight and pathway to circuit simulation of large-scale integration of pixel circuits in active matrix liquid crystal display/active matrix organic light-emitting diodes.

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Acknowledgements

The authors thank the Council of Scientific and Industrial Research (CSIR), Government of India, for the financial support (File No. (09/844(0046)/2018-EMR-I)). The authors thank Dr. C. H. Cheng of National Taiwan Normal University, Taiwan, Dr. Uma Mahendra Kumar, Vellore Institute of Technology, Vellore, and Dr. S. Parthiban of PSG Institute of Advanced Studies, Coimbatore, India. The authors also thank the Editor and the anonymous reviewers for their useful comments and suggestions.

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  1. School of Electronics Engineering, Vellore Institute of Technology, Vellore, 632014, India

    Kadiyam Rajshekar & D. Kannadassan

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  1. Kadiyam Rajshekar
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Kadiyam Rajshekar contributed to the development of a comprehensive density-of-states model for oxide semiconductors and applied the model on thin film transistors of various oxide semiconductors through numerical simulations. D. Kannadassan has supervised and supported the research works with Kadiyam Rajshekar.

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Correspondence to D. Kannadassan.

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Rajshekar, K., Kannadassan, D. A comprehensive density-of-states model for oxide semiconductor thin film transistors. J Comput Electron 20, 2331–2341 (2021). https://doi.org/10.1007/s10825-021-01783-8

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