A lattice gas model of II-VI(001) semiconductor surfaces

Biehl, Michael; Ahr, M.; Kinzel, Wolfgang; Sokołowski, M.; Volkmann, T.

doi:10.1209/epl/i2001-00132-1

Cited by 11 publications

(9 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Measuring energy in units of |ε d |, we set ε d = −1. A model, where the underlying crystal was assumed to be fixed, has been studied elsewhere [11]. If the energy difference between a perfect c(2 × 2) arrangement and a perfect (2 × 1) arrangement is small and positive (−2 < ε x ≤ −1.9), this model explains the c(2 × 2)-(2 × 1) reordering as an accompanying effect of an order-disorder transition in thermal equilibrium.…”

mentioning

confidence: 99%

“…Comparing our solid-on-solid model with the two-dimensional anisotropic lattice gas, we calculate the equilibrium values of C d AA , C x AA in the planar lattice gas model at the value of θ A we measure for AB at a given temperature, which can be done using transfer matrix techniques [11]. Although the non-equilibrium conditions of sublimation enhance the dominance of C However, a simple mapping of the surface layer of the sublimating system on a 2D lattice gas in thermal equilibrium is not possible.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Modelling sublimation and atomic layer epitaxy in the presence of competing surface reconstructions

Ahr

Biehl

2001

Surface Science

View full text Add to dashboard Cite

We present a solid-on-solid model of a binary AB compound, where atoms of type A in the topmost layer interact via anisotropic interactions different from those inside the bulk. Depending on temperature and particle flux, this model displays surface reconstructions similar to those of (001) surfaces of II-VI semiconductors. We show, that our model qualitatively reproduces many of the characteristic features of these materials which have been observed during sublimation and atomic layer epitaxy. We predict some previously unknown effects which might be observed experimentally. Keywords: Monte Carlo simulations, Surface relaxation and reconstruction, Models of nonequilibrium phenomena, Evaporation and sublimation, GrowthApart from a few exceptions (eg.[1]), theoretical models of crystal surfaces in nonequilibrium situations have not taken into account the effects of surface reconstructions, so far. Consequently, a theoretical understanding of the interplay of this phenomenon with the dynamics of growing or sublimating surfaces has not yet been achieved. In this paper we will address this important question in the context of a compound material that displays a competition of different vacancy structures in the terminating layer.Within the last years, there have been intensive experimental studies concerning the surfaces of II-VI semiconductors, see eg. [2,3] for an overview. These studies have revealed the existence of a fairly small number of surface reconstructions, which makes them promising candidates for a theoretical modelling. In the following, we will refer mostly to experimental results for CdTe(001) [2][3][4][5][6][7][8][9]. Under vacuum conditions, the CdTe(001) surface is metal terminated. The Cd atoms arrange in a vacancy structure, where half of the potential Cd sites are empty. At low temperatures, a c(2 × 2) reconstruction is observed, in which Cd atoms arrange in a checkerboard like configuration. Often a contribution of (2 × 1) arrangement in rows along the (110) direction is observed. At a temperature of ≈ 300 0 C, a reordering occurs, above which a (2 × 1) ordering dominates on a sublimating surface. An additional Cd flux stabilizes the c(2 × 2) ordering even at high temperatures. Under a Te flux, the surface is Te-terminated, with a (2 × 1) reconstruction. At small Te fluxes, the Te-coverage is 1, at low temperatures and high Te fluxes a higher coverage of 1.5 is observed [3,5,6,8]. In this Letter, we present a 2+1-dimensional solid-on-solid model of a binary compound material to get insight into the following problems: (1) Is the claim [6] of an effective thermal equilibrium of the surface layer justified under the non-equilibrium conditions of sublimation? (2) What is the effect of an external particle flux on the surface reconstruction? (3) How do reconstructions influence techniques of crystal growth like atomic layer epitaxy (ALE)?In the terminating layer of a CdTe(001) surface, the potential Cd sites form a regular square lattice, where the simultaneous occupation of nearest neighbour (NN...

show abstract

mentioning

confidence: 99%

mentioning

confidence: 99%

Modelling sublimation and atomic layer epitaxy in the presence of competing surface reconstructions

Ahr

Biehl

2001

Surface Science

View full text Add to dashboard Cite

show abstract

“…Despite the fact that significant sublimation sets in even below 570K, the temperature driven re-ordering of the Cd-terminated surface has been discussed in terms of a phase transition in effective equilibrium. 5,8,10,11 Electron counting rules, 12 and density functional theory (DFT) calculations [13][14][15] show that the simultaneous occupation of nearest neighbor (NN) sites in the y-direction should be extremely unlikely within a terminating Cd layer. Such pairs of NN-Cd would lead to an unfavorable local concentration of positive charges.…”

Section: Properties Of the Materials Systemmentioning

confidence: 99%

“…In earlier investigations we employed two-dimensional lattice gas models of the CdTe(001) surface 10,11 for the investigation of the temperature and flux dependence of surface reconstructions. Chemical bonds and the influence of the underlying crystal were accounted for by effective pairwise anisotropic interactions.…”

Section: Introductionmentioning

confidence: 99%

Kinetic model of II-VI(001) semiconductor surfaces: Growth rates in atomic layer epitaxy

2004

View full text Add to dashboard Cite

We present a zinc-blende lattice gas model of II-VI(001) surfaces, which is investigated by means of Kinetic Monte Carlo (KMC) simulations. Anisotropic effective interactions between surface metal atoms allow for the description of, e.g., the sublimation of CdTe(001), including the reconstruction of Cd-terminated surfaces and its dependence on the substrate temperature T . Our model also includes Te-dimerization and the potential presence of excess Te in a reservoir of weakly bound atoms at the surface. We study the self-regulation of atomic layer epitaxy (ALE) and demonstrate how the interplay of the reservoir occupation with the surface kinetics results in two different regimes: at high T the growth rate is limited to 0.5 layers per ALE cycle, whereas at low enough T each cycle adds a complete layer of CdTe. The transition between the two regimes occurs at a characteristic temperature and its dependence on external parameters is studied. Comparing the temperature dependence of the ALE growth rate in our model with experimental results for CdTe we find qualitative agreement.

show abstract

“…Biehl et al introduced the anisotropic two‐dimensional lattice gas model for investigations of the metal‐terminated II–VI (001) semiconductor surfaces 17–20. This model reproduces many of the characteristic features of these materials.…”

Section: Introductionmentioning

confidence: 99%

Density‐functional study on the migration of Cd and Te adsorbates on the (001) surface of CdTe

Patrakov

Fink

et al. 2010

Physica Status Solidi (b)

View full text Add to dashboard Cite

A lattice gas model of II-VI(001) semiconductor surfaces

Cited by 11 publications

References 30 publications

Modelling sublimation and atomic layer epitaxy in the presence of competing surface reconstructions

Modelling sublimation and atomic layer epitaxy in the presence of competing surface reconstructions

Kinetic model of II-VI(001) semiconductor surfaces: Growth rates in atomic layer epitaxy

Density‐functional study on the migration of Cd and Te adsorbates on the (001) surface of CdTe

Contact Info

Product

Resources

About