2019/11/09 by Syed Farid Uddin Farhad, D. Cherns, Farhad, Syed Farid Uddin +7
Materials Science · #Applied Physics (physics.app-ph) #Chemical Physics (physics.chem-ph) #Copper-based nanomaterials and applications #Electronic and Structural Properties of Oxides #FOS: Physical sciences #Materials Science (cond-mat.mtrl-sci) #ZnO doping and properties
paper · pdf · doi:10.48550/arxiv.1911.03727
openalex publication_date 2019/11/09 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Low resistivity (~3-24 mOhm.cm) with tunable n- and p-type phase pure Cu2O\nthin films have been grown by pulsed laser deposition at 25-200 0C by varying\nthe background oxygen partial pressure (O2pp). Capacitance data obtained by\nelectrochemical impedance spectroscopy was used to determine the conductivity\n(n- or p-type), carrier density, and flat band potentials for samples grown on\nindium tin oxide (ITO) at 25 0C. The Hall mobility of the n- and p-type Cu2O\nwas estimated to be ~ 0.85 cm2.V-1s-1 and ~ 4.78 cm2.V-1s-1 respectively for\nsamples grown on quartz substrate at 25 0C. An elevated substrate temperature ~\n200 0C with O2pp = 2 - 3 mTorr yielded p-type Cu2O films with six orders of\nmagnitude higher resistivities in the range ~ 9 - 49 kOhm.cm and mobilities in\nthe range ~ 13.5 - 22.2 cm2.V-1s-1. UV-Vis-NIR diffuse reflectance spectroscopy\nshowed optical bandgaps of Cu2O films in the range of 1.76 to 2.15 eV depending\non O2pp. Thin films grown at oxygen-rich conditions O2pp > 7 mTorr yielded\nmixed-phase copper oxide irrespective of the substrate temperatures and upon\nair annealing at 550 0C for 1 hour completely converted to CuO phase with\nn-type semiconducting properties (~12 Ohm.cm, ~1.50 cm2.V-1s-1). The as-grown\np- and n-type Cu2O showed rectification and a photovoltaic (PV) response in\nsolid junctions with n-ZnO and p-Si electrodes respectively. Our findings may\ncreate new opportunities for devising Cu2O based junctions requiring low\nprocess temperatures.\n