Publication Date:
2002
abstract:
The growth of ZnTe by atmospheric pressure metalorganic vapour phase
epitaxy on (100)ZnTe:P substrates is reported. The epilayers were grown at
340°C after in situ H2 heat cleaning of the substrate for surface oxide
removal. Secondary ion mass spectrometry analysis of as-grown samples has
shown that in situ treatment temperatures above 240°C are necessary.
Moreover, no phosphorous incorporation occurs in the epilayers by either
diffusion from the substrate or auto-doping through the vapour. Carbon is
instead incorporated in the epilayers at concentrations higher than in the
substrate. 4.2K photoluminescence (PL) measurements show a dominant band
edge emission, whose main component at 2.3809eV is identified, by
comparison with reflectance spectra, with the 1s-state free exciton line,
its FWHM being 2.2meV. A weak 2s-state exciton line also appears on the
high-energy side of the ground-state emission, further confirming the high
optical quality and purity of the epilayers. Donor and acceptor bound
exciton lines are also identified within the band edge region, whilst
free-to-bound and donoracceptor pair bands below 2.37eV in the PL spectra
are ascribed to luminescence from the substrate.
epitaxy on (100)ZnTe:P substrates is reported. The epilayers were grown at
340°C after in situ H2 heat cleaning of the substrate for surface oxide
removal. Secondary ion mass spectrometry analysis of as-grown samples has
shown that in situ treatment temperatures above 240°C are necessary.
Moreover, no phosphorous incorporation occurs in the epilayers by either
diffusion from the substrate or auto-doping through the vapour. Carbon is
instead incorporated in the epilayers at concentrations higher than in the
substrate. 4.2K photoluminescence (PL) measurements show a dominant band
edge emission, whose main component at 2.3809eV is identified, by
comparison with reflectance spectra, with the 1s-state free exciton line,
its FWHM being 2.2meV. A weak 2s-state exciton line also appears on the
high-energy side of the ground-state emission, further confirming the high
optical quality and purity of the epilayers. Donor and acceptor bound
exciton lines are also identified within the band edge region, whilst
free-to-bound and donoracceptor pair bands below 2.37eV in the PL spectra
are ascribed to luminescence from the substrate.
Iris type:
01.01 Articolo in rivista
Published in: