Title Thermal analysis of graphene/N-Si(100) diode, formed using transfer-less method /
Authors Jankauskas, Šarūnas ; Gudaitis, Rimantas ; Meškinis, Šarūnas
DOI 10.15388/IOR2023
ISBN 9786090708835
Full Text Download
Is Part of Open readings 2023: 66th international conference for students of physics and natural sciences, April 18-21, 2023, Vilnius, Lithuania: annual abstract book / editors: M. Keršys, Š. Mickus.. Vilnius : Vilnius University press, 2023. p. 224.. ISBN 9786090708835
Abstract [eng] One of the most prominent materials to date, graphene has captured attention of the scientific world with its unmatched mechanical, optical and electronic properties. It’s use as a substitute for metals in Si Schottky junction devices is prospective, especially in solar cell field. Today, the highest power conversion efficiency (PCE) reported for Gr/Si solar cells is 16.61% [1]. Regardless, transfer method from Cu foil to Si substrates is still used as the main graphene synthesis method for graphene based electronics, which is not ideal for mass production. It was shown that microwave plasma enhanced chemical vapor deposition (MW-PECVD) is a viable alternative for direct graphene growth on various dielectric and semiconductor substrates, eliminating the sample contaminations which occur during the transfer process. However, PECVD increases defectiveness and self-doping of graphene, compared to transferred graphene counterparts. This, in turn, decreases graphene/Si solar cell efficiency by affecting charge transport at graphene/Si interface. To understand such changes, thorough studies of current-voltage (I-V) characteristics are needed. Herein, we studied charge transport mechanisms at different operating temperature regimes of transfer-less graphene/n- Si(100) diodes, to understand such drop in performance. In this work, graphene was grown on the Si(100) substrates by using MW-PECVD system (IPLAS Innovative Plasma Systems GmbH). Diodes were fabricated by growing Al back contact (on Si side) and forming cylindrical Cr/Cu electrodes on top of graphene. The characterization of samples was carried out using Raman scattering spectroscopy (Renishaw inVia, 532 nm) prior to diode formation as well as evaluating fabricated photovoltaic device I-V characteristics (Keithley 6487 picoampere meter/voltage source) with thermal operational conditions being changed (from -20 °C to 40 °C) by a custom-made Peltier element configuration. Raman spectra appeared to be typical for PECVD graphene grown on Si. Measured I-V characteristics showed an increase of current (from 0.026 mA to 0.067 mA at 1 V) with temperature increase (from -20 °C to 40 °C) (Fig. 1). By analysing charge transport mechanisms, it was evident that graphene exhibits tunnelling at low temperatures and combined tunnelling with thermionic emission mechanism, when temperatures are higher. [...].
Published Vilnius : Vilnius University press, 2023
Type Conference paper
Language English
Publication date 2023
CC license CC license description