PHOTOLUMINESCENCE STUDIES OF GaInArSb HIGHLY DOPED WITH TELLURIUM GROWN BY LIQUID PHASE EPITAXY ON (100) GaSb (original) (raw)
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Low temperature photoluminescence of tellurium-doped GaSb grown by molecular beam epitaxy
Journal of Crystal Growth, 1996
We present the first systematic study of photoluminescence (PL) of GaSb grown by molecular beam epitaxy and Te doped at levels ranging from non-intentional to high. The PL spectra show features that gradually evolve with the doping level. The main structure of the PL spectra of the nominally undoped sample is a band attributed to the native double acceptor defect, which determines the p-type conductivity. In doped samples, the evidence of levels directly connected with tellurium has been found. At low doping levels we observe the recombination of free holes with electrons bound to the Te hydrogenic donor, while in heavily doped samples the dominant feature is a deep PL band attributed to a complex involving incorporated Te and structural defects. The observed blue shift of the PL bands as the doping level increases is consistent with the occurrence of band-filling effects.
Photoluminescence of liquid‐phase epitaxial Te‐doped GaSb
Journal of Applied Physics, 1993
The photoluminescence (PL) spectra of Te-doped GaSb epitaxial layers grown from Ga-rich solutions by liquid-phase epitaxy have been studied in the electron concentrations from 8 X lOI to 4X IO'* cme3. The electron concentration can be accurately controlled by varying the growth temperature and adding the polycrystalline Te-doped GaSb to replace half or all the undoped GaSb starting material in the growth solution. The dependence of line position, line intensity, spectral shape, and broadening on the doping level, power excitation, and temperature has been investigated in detail. At concentrations as low as 1 X 1Or6 cmb3, the GaSb sample has become degenerate because of the small effective mass of electrons and the broad band consisting of five partially resolved line dominates the low-temperature PL spectra. At concentrations above 1 X 10" cm-s, the 19 K PL spectra is mainly dominated by the sub-band-gap, substrate-induced line A' at 775.8 meV which is enhanced by the scattering of light off the back surface. This line A' is direct evidence for the band-gap shrinkage at high doping level. This is the first report to present the detailed luminescence lines in the PL spectra of the Te-doped GaSb samples.
Journal of Physics-condensed Matter, 2003
Controlled doping of quaternary alloys of InxGa1-xAsySb1-y with tellurium is fundamental to obtain the n-type layers needed for the development of optoelectronic devices based on p-n heterojunctions. InGaAsSb epitaxial layers were grown by liquid phase epitaxy and Te doping was obtained by incorporating small Sb3Te2 pellets in the growth melt. The tellurium doping levels were in the range 1016-1017 cm-3. We have used low-temperature photoluminescence (PL) spectroscopy to study the influence of the Te donor levels on the radiative transitions shown in the PL spectra. The PL measurements were done by exciting the samples with the 448 nm line of an Ar ion laser with varying excitation powers in the range from 10 to 200 mW. For the low-doped sample the PL spectrum showed a narrow exciton-related peak centred at around 610 meV with a full width at half maximum (FWHM) of about 7 meV which is evidence of the good crystalline quality of the layers. For higher Te doping, the PL spectra show the presence of band-to-band and donor-to-acceptor transitions which overlap as the Te concentration increases. The peak of the PL band shifts to higher energies as Te doping increases due to a band-filling effect as the Fermi level enters into the conduction band. From the peak energy of the PL spectra, and using a model that includes the band-filling and band-shrinkage effects due to the carriers, we have estimated the effective carrier concentration due to doping with Te in the epilayers.
Nature of compensating luminescence centers in Te‐diffused and ‐doped GaSb
Journal of Applied Physics, 1996
Diffusion of tellurium in undoped p-GaSb has been carried out. Using the cathodoluminescence and photoluminescence techniques, the luminescence centers in Te-diffused samples have been identified and compared with the Te-doped bulk GaSb. Fundamental differences in the radiative levels are observed between the diffused and the as-grown doped samples. Evidence for self-compensating acceptor complexes are seen in diffused samples. With short and moderate diffusion times, a compensating acceptor complex V Ga Ga Sb Te Sb is observed. For long diffusion times, the dominant acceptor center has been attributed to the antisite defect Ga Sb or related complex. The reasons for the formation of various acceptor centers have been discussed.
physica status solidi (c), 2004
ABSTRACT The influence of tellurium doping on the optical properties of InxGa1–xAsySb1–y epitaxial layers has been studied by photoluminescence (PL) spectroscopy. PL was carried out by exciting the sample with the 488-nm line of an Ar-ion laser, changing the exciting power in the range between 40–200 mW and varying the temperature in the range 15–300 K. For the low-doped sample the PL spectrum showed a narrow exciton-related peak at 648.6 meV with a full width at half maximum (FWHM) of about 7 meV, which is an evidence of the good crystalline quality of the layers. For higher Te doping, the PL spectra showed the presence of band-to-band and donor-to-acceptor transitions which overlap as the Te concentration increases. The peak of the PL band shifts to higher energies as Te doping increases due to a band-filling effect as the Fermi level enters into the conduction band. The temperature dependence of the PL spectra for those samples with higher Te doping show a broad band at intermediate energies which disappear for temperatures above 80 K which is a typical behavior for a transition associated to DX deep defects. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
Applied Physics Letters, 2022
Quinary GaInAsSbBi is grown by molecular beam epitaxy, and the alloy is demonstrated with a bandgap energy of 291 meV (λcutoff ∼ 4.3 μm) and a minority carrier lifetime of 0.34 μs at 120 K. The GaInAsSbBi epilayer is grown to a thickness of 1 μm at 400 °C and lattice-matched to the GaSb substrate with a Bi mole fraction of 0.13% measured by Rutherford backscattering spectroscopy. Steady-state and time-resolved photoluminescence measurements are performed to gauge the comparative bandgaps and optical quality of GaInAsSbBi as well as InAsSbBi and GaInAsSb reference samples. A recombination rate analysis is performed on the low-injection temperature-dependent minority carrier lifetime to extract the Shockley–Read–Hall defect level and intrinsic doping concentration of the GaInAsSbBi.
Journal de Physique IV (Proceedings), 2006
Using the liquid phase epitaxy technique under supercooling conditions we have grown In 0.14 Ga 0.86 As 0.13 Sb 0.87 layers doped with tellurium lattice-matched to (100) n-GaSb substrates. Layers doped with tellurium were accomplished by incorporation of Sb 2 Te 3 pellets into the growth melt in different concentrations, in the range of 6.48 × 10 −6 to 4.31 × 10 −4 molar fraction. Using Raman scattering we characterized the structural quality. The Raman spectra show two main peaks located about 150 and 265 cm −1 , which were deconvoluted by four Lorentzians. In order to assign the peaks use is made of the random-element isodisplacement (REI) model. Comparison of the experimental results with the values obtained by REI model allows us to confirm that the bands correspond to the LO-like and TO-like of the binary compounds, GaAs and (GaSb+InAs).
Low-Temperature Photoluminescence of In0.14Ga0.86As0.13Sb0.87 Solid Solution Lattice Matched to GaSb
Crystal Growth & Design, 2009
A low-temperature photoluminescence (PL) study of liquid phase epitaxy grown undoped and Te-doped In 0.14 Ga 0.86 As 0.13 Sb 0.87 layers lattice matched to n-type GaSb is reported. The quaternary solid solutions In x Ga 1-x As y Sb 12y are promising materials for the fabrication of optoelectronics devices operating in the spectral range of 3-5 µm because these alloys can form type II heterojunctions with both staggered and broken-gap alignments. The PL for the undoped InGaAsSb layer shows three narrow exciton-related peaks with narrow full width at half-maximum (FWHM), which is an evidence of the good crystalline quality of the epilayers. The PL spectrum for a slight Te-doped InGaAsSb layer shows a red shift, which is more remarkable for high excitation powers. When increasing the Te-doping in the quaternary alloys, the PL spectra show that the donor-to-acceptor radiative transition associated with neutral tellurium and a neutral acceptor is dominant, although the band-to-band transition is present too.
Revista Mexicana De Fisica, 2017
Ga$_{0.86}$In$_{0.14}$As$_{0.13}$Sb$_{0.87}$ layers lattice-matched to (100) Te-GaSb have been grown using the liquid phase epitaxy technique under supercooling conditions. N and p type layers were grown by adding tellurium or zinc in a wide range of molar fraction in the growth solution. By Raman spectroscopy, the structural quality of the epilayers was characterized. The Raman spectra show that the layers become more defective as the dopant molar fraction is increased, n - or p -type. Two main bands are observed in the Raman spectra centered at 230 and 245~cm$^{-1}$ that depend strongly on the incorporated dopant molar concentration (Te or Zn), which are assigned to the observed vibrational modes of GaAs-like and (GaSb+InAs)-like mixture. The low-temperature photoluminescence of nnn (or ppp)-type GaInAsSb was measured as function of dopant concentration added to the melt solution. The photoluminescence spectra were interpreted taking into account the nonparabolicity of the conduct...
Photoluminescence of GaSb grown by metal-organic vapour phase epitaxy
Semiconductor Science and Technology, 1991
Low-temperature photolLminescence of epitaxial GaSb grown by M O~P E from TMGa and TMSb on various sdbstrates is studied an0 compared witn exist ng results for GaSb grown oy otner techniques. The enecls of growth condit o n s are cons dereo It is touno that a growtn IemperatJre of 650 .C is too h gh, ana tne layers are of v e r y poor qdality. while below t h e opt mLm temperature of 600 ' C tne growth rate slows. a thoLgh t h e optica quality appears unaftected. lnvestigations into tne range of IIIV ratios over wh ch good qLal ty mater al cou d be grown indicated that I n s factor was more critica for GaSo than for GaAs; So-rich condit.ons proddceo samples w In poor radial ve etlic ency. whale samples grown under Ga-r ch conditions were covered on excess Ga orop ets. n addition. w e found that m common witn otner growth techniqdes, the concentrat on of t h e nat ve aefect n GaSb cou d be controlled dsing the l l l V ratio. and an excel e n t corre ation was found between electrical resu ts and features in tne pnoto um nescence Spectra For layers not lahlce-matcnea 10 t h e substrate. t h e spectrum IS red-sniheo W e surm se tnat th s is d u e to dilferenlia thermal contract on of t h e e p layer and substrate A homoepitaxial sample was chosen for aeta led stday ana lrom the depenaence 01 tho spectra on temperatLre and excitation ntensity. a previoLsiy ooserved bOdnd exciton was confirmed and an acceptor of 15 meV bind,ng energy was founo