Pulsed-laser-deposited, single-crystalline Cu2O films with low resistivity achieved through manipulating the oxygen pressure

Abstract Low-resistivity, single-crystalline Cu 2 O films were realized on MgO (110) substrates through manipulating the oxygen pressure (P O2 ) of pulsed-laser deposition. X-ray diffraction and high resolution transmission electron microscopy measurements revealed that the films deposited at P O2 of 0.06 and 0.09 Pa were single phase Cu 2 O and the 0.09-Pa-deposited film exhibited the best crystallinity with an epitaxial relationship of Cu 2 O (110)∥MgO (110) with Cu 2 O (001)∥MgO (001). The pure phase Cu 2 O films exhibited higher transmittances and larger band gaps with an optical band gap of 2.56 eV obtained for the 0.09 Pa-deposited film. Hall-effect measurements demonstrated that the Cu 2 O film deposited at 0.09 Pa had the lowest resistivity of 6.67 Ω cm and highest Hall mobility of 23.75 cm 2  v −1  s −1 .