MBE Growth and Properties of InN and InN-based diluted magnetic semiconductors

摘要

InN films were grown by N_2 plasma-assisted molecular beam epitaxy (MBE) on Al_2O_3 substrates. The films were characterized by reflection high-energy electron diffraction, atomic force microscope, x-ray diffraction methods and Raman spectrum, indicating high crystalline quality of the films. The optical absorption and photoluminescence measurement show the band-gap energy of InN films was located about 1.0-1.1 eV. InN-based diluted magnetic semiconductor (DMS) In_(1-x)Mn_xN and In_(1-x)Cr_xN films were prepared by N_2 plasma-assisted MBE at low temperature. Microstructure characterization indicates Mn was homogeneously incorporated into InN up to 4% and 10% respectively at 300℃ and 200℃, while Cr was incorporated up to 4% at 300℃. A paramagnetic to spin-glass transition was observed at 3 K in In_(0.9)Mn_(0.1)N films grown at 200℃. Room temperature ferromagnetism was observed for the homogeneous In_(0.98)Cr_(0.02)N films.