M. Kuzmin

Initial stages of Yb/Si(1 0 0) interface growth: 2 × 3 and 2 × 6 reconstructions

Abstract The initial stages of Yb/Si(1xa00xa00) interface growth have been studied by scanning tunneling microscopy, low-energy electron diffraction, Auger electron spectroscopy (AES), thermal desorption spectroscopy, and work-function change measurements. It is shown that a two-dimensional (2D) adsorbed layer of Yb forms at low coverage (

Does Bi form clusters in GaAs1-xBix alloys?

GaAs1 - xBix alloys attract significant interest due to their potentiality for several applications, including solar cells. Recent experiments link the crucial optical properties of these alloys to ...

Two series of triple- and single-domain reconstructions induced by europium on vicinal Si(1 1 1) []-miscut surface

Abstract The growth and properties of Eu-induced one-dimensional reconstructions on vicinal Si(1xa01xa01) surface miscut in the [ 1 1 2 ] direction have been studied by low energy electron diffraction and scanning tunneling microscope in the submonolayer range. The focus has been attended to the formation of single-domain structures and the influence of preparation parameters on the domain orientation. We have found the critical conditions for the preparation of a variety of Eu-induced single-domain ( n ×2) and ( n ×1) structures. In addition, a new intermediate phase showing the 9×1 periodicity between 3×2 and 2×1 phases is detected.

Growth and properties of crystalline barium oxide on the GaAs(100) substrate

Growing a crystalline oxide film on III-V semiconductor renders possible approaches to improve operation of electronics and optoelectronics heterostructures such as oxide/semiconductor junctions for transistors and window layers for solar cells. We demonstrate the growth of crystalline barium oxide (BaO) on GaAs(100) at low temperatures, even down to room temperature. Photoluminescence (PL) measurements reveal that the amount of interface defects is reduced for BaO/GaAs, compared to Al2O3/GaAs, suggesting that BaO is a useful buffer layer to passivate the surface of the III-V device material. PL and photoemission data show that the produced junction tolerates the post heating around 600u2009°C.

Oxidized crystalline (3 x 1)-O surface phases of InAs and InSb studied by high-resolution photoelectron spectroscopy

The pre-oxidized crystalline (3×1)-O structure of InAs(100) has been recently found to significantly improve insulator/InAs junctions for devices, but the atomic structure and formation of this useful oxide layer are not well understood. We report high-resolution photoelectron spectroscopy analysis of (3×1)-O on InAs(100) and InSb(100). The findings reveal that the atomic structure of (3×1)-O consists of In atoms with unexpected negative (between −0.64 and −0.47u2009eV) and only moderate positive (In2O type) core-level shifts; highly oxidized group-V sites; and four different oxygen sites. These fingerprint shifts are compared to those of previously studied oxides of III-V to elucidate oxidation processes.

Oxidation of GaSb(100) and its control studied by scanning tunneling microscopy and spectroscopy

Atomic-scale knowledge and control of oxidation of GaSb(100), which is a potential interface for energy-efficient transistors, are still incomplete, largely due to an amorphous structure of GaSb(100) oxides. We elucidate these issues with scanning-tunneling microscopy and spectroscopy. The unveiled oxidation-induced building blocks cause defect states above Fermi level around the conduction-band edge. By interconnecting the results to previous photoemission findings, we suggest that the oxidation starts with substituting second-layer Sb sites by oxygen. Adding small amount of indium on GaSb(100), resulting in a (4u2009×u20092)-In reconstruction, before oxidation produces a previously unreported, crystalline oxidized layer of (1u2009×u20093)-O free of gap states.

Ultrathin (1x2)-Sn layer on GaAs(100) and InAs(100) substrates: A catalyst for removal of amorphous surface oxides

Amorphous surface oxides of III-V semiconductors are harmful in many contexts of device development. Using low-energy electron diffraction and photoelectron spectroscopy, we demonstrate that surface oxides formed at Sn-capped GaAs(100) and InAs(100) surfaces in air are effectively removed by heating. This Sn-mediated oxide desorption procedure results in the initial well-defined Sn-stabilized (1x2) surface even for samples exposed to air for a prolonged time. Based on ab initio calculations we propose that the phenomenon is due to indirect and direct effects of Sn. The Sn-induced surface composition weakens oxygen adsorption.