Structural, Optical and Electrical Properties of Nanocrystalline Cu2O Thin Films Grown by Pulsed Laser Deposition

Published: 24 May 2020| Version 1 | DOI: 10.17632/whksg7scsx.1
Syed F. U. Farhad,
David Cherns


S.F.U. Farhad and D. Cherns, “Structural, Optical and Electrical properties of nanocrystalline Cu2O thin films grown by Pulsed Laser Deposition” paper# J8.30 Document: # 1868681 at Symposium J: Physics of Oxide Thin Films and Heterostructures, Material Research Society (MRS), Spring Meeting and Exhibition, 20-25 April, 2014, San Francisco, CA, USA Abstract: Phase pure Cu2O is desirable as an absorber material for solar cells using ZnO electrodes because of its reported bandgap (~2.1 eV), a suitable band alignment with ZnO, and the ability to dope both n- and p-type. Pulsed laser deposition (PLD) has been used to grow Cu2O on ZnO and other substrates at low substrate temperatures and in oxygen ambient. Transmission electron microscopy and X-ray diffraction analyses showed a single phase Cu2O with (111) and (200) textures while growing at 200 C and 25 C substrate temperatures respectively. Electrical measurements, including conductivity and electrochemical Mott-Schottky measurements, showed n-type behaviour with resistivity as low as ~3×10^-2 Ω.cm, much lower than previously reported results at ~25 C without any oxygen injection in the PLD chamber. The as grown Cu2O thin films also showed a transition from highly conductive n-type to highly resistive (~4×10^4 Ω.cm) p-type behaviour as the oxygen concentration increased. UV-Vis diffuse reflectance spectroscopy was used to estimate the optical bandgap of the polycrystalline thin films to be in the range 2.01 -2.10 eV. The poster describes the growth, structural and electrical properties of the Cu2O films, and the properties of Cu2O solar cells grown on ZnO electrodes.