High quality InAs grown by liquid phase epitaxy using gadolinium gettering

Abstract

In this paper, we report the growth of very pure InAs epitaxial layers of high quantum efficiency, by introducing the rare-earth element Gd into the liquid phase during LPE growth. We find that the carrier concentration of InAs layers can be effectively reduced to ∼6 × 10 15 cm −3 . Also, the peak photoluminescence (PL) intensity of such layers can be considerably increased by between ten-and 100-fold compared with untreated material. We attribute this behaviour to the gettering of residual impurities and corresponding reduction of non-radiative recombination centres in the presence of Gd. Four intense sharp lines dominated the low temperature (4 K) photoluminescense spectra of Gd-treated InAs layers. The strongest two of these were found to originate from (a) bound excitons, and (b) donor-acceptor recombination, whereas the remaining two, (c) and (d), were associated with defect-related recombination. The linewidth (FWHM) of the exciton peak (a) was reduced to only 3.8 meV, which is narrower than for undoped epitaxial InAs grown by MBE or MOVPE.

Low Bandgap InAs-Based Thermophotovoltaic Cells for Heat-Electricity Conversion

“…To reduce the residual carrier concentration in the InAs active region, we employed a Gd gettering technique to remove impurities from the active region during growth. 23 Epitaxial layers of unintentionally doped InAs and p-type Zn-doped $1 9 10 18 cm À3 , quaternary InAsSbP were grown nominally latticematched onto n-type, 2 9 10 18 cm À3 InAs (100) substrates by conventional LPE using a horizontal sliding boat technique. Growth was implemented from In-rich melts at temperatures within the interval of 570-580°C based on our previous work, 10 using supercooling, DT $ 3°C.…”

Role of Rare-Earth Elements in the Technology of III-V Semiconductors Prepared by Liquid Phase Epitaxy

“…The author suggests that Gd is not incorporated into the GaAs layers. The more recent paper of Gao (Gao et al, 1999) reports the growth of very pure InAs by introducing Gd into the growth melt. Gao stresses that LPE growth occurs at thermodynamic equilibrium, and in comparison with MBE or MOVPE, the resulting crystalline perfection is superior with few defects.…”

Electrical characterisation of Sn doped InAs grown by MOVPE

“…InAs is a direct, narrow band gap semiconductor which has become one of the most attractive materials for the fabrication of optoelectronic devices [1]. In order to tailor the material for these applications, it is imperative to have a thorough understanding of the behaviour of dopants and subsequently, to have precise control over the growth of the material [2].…”