Estimation of front and back junctions of CZTSe:Ge solar cells by combined modulus and impedance spectroscopy

Sanghyun Lee, Kent J. Price, Edgardo Saucedo

    Research output: Contribution to journalArticlepeer-review

    2 Scopus citations


    We have fabricated and investigated CTSe:Ge bi-layer devices by modulus spectroscopy combined with impedance spectroscopy to understand the electrical properties of hetero- and back-contact junctions. The equivalent circuit model is developed to decouple the properties of each junction at different frequency ranges. Modeling and numerical simulations with the in-house MATLAB modeling suites connected to external simulators, such as Sentaurus TCAD and LEVM/LEVMW software are conducted to estimate the impact of each junction component to modulus and impedance spectroscopy with a parallel equivalent circuit combination of resistance and capacitance components. The fabricated devices show doping concentration of 6.4 1015/cm3, and the conversion efficiency is 8.1% based on capacitance-voltage and current-voltage characterization. From the characterization and modeling, the built-in potential of the hetero-junction is estimated as 801 meV, which is ∼10% smaller than the ideal case from TCAD, 894 meV. Conversely, the built-in potential of the back contact junction is 428 meV. The total apparent built-in potential is estimated to be 373 meV from the Mott-Schottky equation.

    Original languageEnglish
    Article number335501
    JournalJournal of Physics D: Applied Physics
    Issue number33
    StatePublished - Aug 2021

    Bibliographical note

    Funding Information:
    This work was partially supported by Duke Energy Foundation, and CSRC at Indiana State University.

    Publisher Copyright:
    © 2021 IOP Publishing Ltd.

    ASJC Scopus subject areas

    • Electronic, Optical and Magnetic Materials
    • Condensed Matter Physics
    • Acoustics and Ultrasonics
    • Surfaces, Coatings and Films


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