High-purity AlGaAs grown by molecular beam epitaxy using a superlattice buffer layer

Abstract

High-purity Al0.3Ga0.7As is grown by molecular beam epitaxy at a high substrate temperature using a superlattice buffer layer in order to trap residual impurities. The unintentionally doped layer is p type with p < 5×1014 cm−3. Photoluminescence spectra at 10 K showed the strong bound-exciton emission to be 3.8 meV wide and extremely weak emission due to residual C and Si. Photoluminescence spectra of successively grown single-quantum wells with different widths demonstrate that residual C and Si are mainly trapped at the interface of the first-grown well.

Tunable superlattice p-i-n photodetectors: characteristics, theory, and application

“…The following layers were sequentially grown on an n + -GaAs substrate: a l. 0 11m thick n + -GaAs buffer layer ( [25]. [26]. As will be shown in Section III-A, a low doping level in the superlattice is important for the wavelength selectivity of the SLPD.…”

“…where E(k,) (26) li 1 ( )2 Eo= 2~* :,, (27) To account for the finite barrier heights, we use an effective quantum well width L.,. such that E" equals the ground state energy (s = I) calculated from (2) using the true quantum well width.…”

III–V Technology: The Key for Advanced Devices

“…Only one such layer, with a thickness of about 2-4 tzm, is required to achieve the improvement. This is to compare with the intermediate growth of a (strained) superlattice which also allows for enhancement of the material quality and which is effectively used in the case of the heteroepitaxial growth of III-V materials onto various substrates, see, e.g., (7)(8)(9). However no complicated growth system is needed.…”