Desorption of hydrogen from InN(000(1)over-bar) observed by HREELS


Bhatta R., Thoms B. D. , ALEVLİ M. , Dietz N.

SURFACE SCIENCE, cilt.602, sa.7, ss.1428-1432, 2008 (SCI İndekslerine Giren Dergi) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 602 Konu: 7
  • Basım Tarihi: 2008
  • Doi Numarası: 10.1016/j.susc.2008.02.003
  • Dergi Adı: SURFACE SCIENCE
  • Sayfa Sayıları: ss.1428-1432

Özet

The kinetics of isothermal desorption of hydrogen from InN(000 (1) over bar) have been investigated using surface vibrational spectroscopy. Reductions in intensity of the N-H stretching and bending vibrations in high resolution electron energy loss spectra (HREELS) upon annealing indicated loss of surface hydrogen and was attributed to recombinative desorption. Hydrogen completely desorbs from the InN surface upon annealing for 900 s at 425 degrees C or upon annealing for 30 s at 500 degrees C. Surface hydrogen coverage was determined using the intensity of the N-H stretching vibrational loss peak. Fitting the coverage versus temperature for anneals of either 30 or 900 s indicated that the desorption was best described by second-order desorption kinetics with an activation energy and pre-exponential factor of 1.3 +/- 0.2 eV and 10(-7.3 +/- 1.0) cm(2)/s, respectively. In addition to thermal desorption, an increase in the carrier concentration in the film was also observed upon annealing to 450 degrees C or higher as shown in HREELS by a shift of the conduction band plasmon excitation to higher energy. (c) 2008 Elsevier B.V. All rights reserved.