Characterization of homoepitaxial p-type ZnO grown by molecular beam epitaxy

Abstract

An N-doped, p-type ZnO layer has been grown by molecular beam epitaxy on an Li-diffused, bulk, semi-insulating ZnO substrate. Hall-effect and conductivity measurements on the layer give: resistivity=4×101cm; holemobility=2cm2/Vs; and hole concentration=9×10 16cm-3. Photoluminescence measurements in this N-doped layer show a much stronger peak near 3.32 eV (probably due to neutral acceptor bound excitons), than at 3.36 eV (neutral donor bound excitons), whereas the opposite is true in undoped ZnO. Calibrated, secondary-ion mass spectroscopy measurements show an N surface concentration of about 1019cm -3 in the N-doped sample, but only about 1017cm -3 in the undoped sample. © 2002 American Institute of Physics.