Growth of p-type ZnTe thin films by using nitrogen doping during pulsed laser deposition

Abstract

P-type ZnTe thin films were grown on sapphire substrates by using nitrogen doping during pulsed laser deposition. The nitrogen doping was controlled by using the N2 gas pressure, which ranged from 0.1 to 70 mTorr. X-ray diffraction showed the ZnTe films to have a cubic zinc-blende structure, and the full width at half maximum (FWHM) of the (111) peak of undoped ZnTe film was 1.05°, but the FWHM and the intensity of the (111) peak decreased with increasing nitrogen doping. From Raman spectroscopy measurements, Te A1 and Te E LO modes appeared in all ZnTe films, with the 1LO, 2LO, and 3LO modes decreasing with increasing N2 pressure. The samples grown at N2 pressures of 50 and 70 mTorr showed a N-Zn bond with binding energy of 397.1 eV and with nitrogen contents of 2.6 and 4.7 at%, respectively. From these results, incorporation of nitrogen atoms into ZnTe film was more efficient at high N2 pressure of 70 mTorr, at which the hole concentration of the N-doped ZnTe film was about 9.61 × 1017 cm −3.