Growth properties of GaSb: The structure of the residual acceptor centres
TL;DR: In this article, the influence of direction of growth, melt composition and growth speed upon the relative occurrence of the residual acceptor centers in melt-grown GaSb single crystals was studied.
About: This article is published in Journal of Physics and Chemistry of Solids.The article was published on 1967-01-01. It has received 142 citations till now.
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TL;DR: In this article, Fermi level stabilizes after a small fraction of a monolayer of either metal or oxygen atoms have been placed on the surface of the semiconductor.
Abstract: For n- and p-doped III-V compounds, Fermi-level pinning and accompanying phenomena of the (110) cleavage surface have been studied carefully using photoemission at hv≲ 300 eV (so that core as well as valence band levels could be studied). Both the clean surfaces and the changes produced, as metals or oxygen are added to those surfaces in submonolayer quantities, have been examined. It is found that, in general, the Fermi level stabilizes after a small fraction of a monolayer of either metal or oxygen atoms have been placed on the surface. Most strikingly, Fermi-level pinning produced on a given semiconductor by metals and oxygen are similar. However, there is a strong difference in these pinning positions depending on the semiconductor: The pinning position is near (1) the conduction band maximum (CBM) for InP, (2) midgap for GaAs, and (3) the valence band maximum (VBM) for GaSb. The similarity in the pinning position on a given semiconductor produced by both metals and oxygen suggests that the states responsible for the pinning resulted from interaction between the adatoms and the semiconductor. Support for formation of defect levels in the semiconductor at or near the surface is found in the appearance of semiconductor atoms in the metal and in disorder in the valence band with a few percent of oxygen. Based on the available information on Fermi energy pinning, a model is developed for each semiconductor with two different electronic levels which are produced by removal of anions or cations from their normal positions in the surface region of the semiconductors. The pinning levels have the following locations, with respect to the VBM: GaAs, 0.75 and 0.5 eV; InP, 0.9 and 1.2 eV (all levels + 0.1 eV).
779 citations
TL;DR: The 3-V ternaries and quaternaries (AlGaIn)(AsSb) lattice matched to GaSb is a promising material for high speed electronic and long wavelength photonic devices.
Abstract: Recent advances in nonsilica fiber technology have prompted the development of suitable materials for devices operating beyond 155 mu m The III-V ternaries and quaternaries (AlGaIn)(AsSb) lattice matched to GaSb seem to be the obvious choice and have turned out to be promising candidates for high speed electronic and long wavelength photonic devices Consequently, there has been tremendous upthrust in research activities of GaSb-based systems As a matter of fact, this compound has proved to be an interesting material for both basic and applied research At present, GaSb technology is in its infancy and considerable research has to be carried out before it can be employed for large scale device fabrication This article presents an up to date comprehensive account of research carried out hitherto It explores in detail the material aspects of GaSb starting from crystal growth in bulk and epitaxial form, post growth material processing to device feasibility An overview of the lattice, electronic, transport, optical and device related properties is presented Some of the current areas of research and development have been critically reviewed and their significance for both understanding the basic physics as well as for device applications are addressed These include the role of defects and impurities on the structural, optical and electrical properties of the material, various techniques employed for surface and bulk defect passivation and their effect on the device characteristics, development of novel device structures, etc Several avenues where further work is required in order to upgrade this III-V compound for optoelectronic devices are listed It is concluded that the present day knowledge in this material system is sufficient to understand the basic properties and what should be more vigorously pursued is their implementation for device fabrication (C) 1997 American Institute of Physics
655 citations
TL;DR: In this paper, the formation of Au Schottky barrier on cleaved GaSb, GaAs, and InP was investigated using photoemission spectroscopy and ion-depth profiling techniques.
Abstract: Photoemission spectroscopy, constant-final-state spectroscopy, and ion-depth profiling techniques were applied to the study of the formation of Au Schottky barrier on cleaved GaSb, GaAs, and InP. It is found that the deposited Au interacts strongly with the semiconductors, causing decomposition of their surfaces. Further, the Fermi-level pinning is nearly complete at < 0.2-monolayer Au coverage, when the Au is still ''atomiclike.'' It is suggested that defect states at the interface are responsible for the Schottky-barrier pinning, and a mechanism for their creation is proposed. It appears that many of the known phenomena on Schottky barriers can be explained using a ''defect'' model proposed here.
136 citations
TL;DR: A doubly ionizable acceptor (EA = 34.5 meV, EC = 102 meV), which is responsible for the hole concentration in undoped GaSb, is identified by photoluminescence experiments at 2 K.
Abstract: A doubly ionizable acceptor (binding energies of EA = 34.5 meV, EC = 102 meV), which is responsible for the hole concentration in undoped GaSb, is identified by photoluminescence experiments at 2 K. Growth experiments, using nonstoichiometric melts, show that this acceptor is connected with a lack of antimony in the crystals. Experimental photoluminescence data, concerning the free exciton recombination at 810 meV and an emission line at 795.5 meV (possibly a bound exciton) as well as new phonon satellites, are presented. Finally, photoconductance measurements at the same samples give further information about excitons in GaSb.
Der doppelt ionisierbare Akzeptor (Bindungsenergien EA = 34,5 meV und EC = 102 meV), der die hohe Locherkonzentration in undotiertem GaSb verursacht, wird durch Photolumineszenzexperimente bei 2 K identifiziert. Untersuchungen an Kristallen, die aus Schmelzen mit unterschiedlichem Antimongehalt gezogen wurden, zeigen, das dieser Akzeptor auf einem Mangel an Antimon im Kristall beruht. Weiterhin wird uber experimentelle Photolumineszenzdaten berichtet, die sowohl die Rekombination des freien Exzitons bei 810 meV und eine Emissionslinie bei 795,5 meV (wahrscheinlich ein gebundenes Exziton) als auch neue Phononensatelliten betreffen. Schlieslich geben Photoleitfahigkeitsmessungen an den gleichen Proben weitere Information uber Exzitonen in GaSb.
98 citations
TL;DR: In this article, the effect of interface shape changes and on and off facet growth on the impurity distribution of GaSb was investigated and the most important correction to the distribution constant was shown to be based on interface shape change and on-off facet growth as freezing proceeds.
95 citations
References
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TL;DR: Germanium single crystals frequently show considerable cross-sectional resistivity variations as mentioned in this paper, and the dependence of these variations upon crystal orientation as well as upon the shape of the solid liquid interface during crystal growth has been investigated.
Abstract: Germanium single crystals frequently show considerable cross-sectional resistivity variations. The dependence of these variations upon crystal orientation as well as upon the shape of the solid-liquid interface during crystal growth has been investigated. It appears that a direct relationship exists between the crystal orientation, the shape of the growth interface and the occurrence of persistent cross-sectional resistivity variations. The origin of these variations is closely related to the presence of a flat facet on the otherwise curved growth interface, which facet coincides with a {111} plane. The segregation constants of several impurities appear to be different for the flat part and for the curved part of the growth interface, thus causing cross-sectional variations of the impurity concentration. Methods for preventing these variations are discussed.
90 citations
TL;DR: In this article, the p-type nature of GaSb is due to lattice defects rather than to impurities, and the best sample measured had a hole concentration of 9.2 × 1015cm−3 and a Hall mobility of 5230 cm2/V sec at 77°K.
89 citations
TL;DR: In this article, the heats of formation of the III-V compounds InSb, GaSb and InAs at 0°C were measured by tin solution calorimetry.
76 citations
TL;DR: In this paper, self-diffusion measurements have been made in the semi-conducting interrnetallic compounds InSb and GaSb using a tracer technique in which layer's were removed from the crystal progressively and the residual activity in the crystal was counted after each section was taken.
71 citations
TL;DR: In this paper, the electrical properties of p-type GaSb containing lithium have been measured over the temperature range 20 −400°K and it was found that introduction of lithium by diffusion at temperatures below 500°C results in reduced hole concentrations and increased Hall mobilities.
66 citations