Quasi‐Classical Quantization for Potentials with an Infinite Surface Barrier. Subbands in Inversion Layers

The galvanomagnetic properties of conduction electrons in n-type inversion layers adjacent to the grain boundary in p-type InSb bicrystals in magnetic fields up to 18 T and temperatures down to 2 K are investigated. The observed quantum oscillations of the magnetoresistivity result from a superposition of the Shubnikov-de Haas effect in two occupied subbands. The electron densities of subbands ngi (nS1 = 3.5 x lo1' cm-Z; nso = 1.1 x 10l2 cm-2) and the effective cyclotron mass of the subbands mci Simultaneously the diagonal resistivity ezz drops to a minimum. Other characteristic features of a two-dimensional electron gas confined in the symmetrical potential well of the grain boundary are obtained. Es werden die Magnetotransporteigenschaften der Leitungselektronen in n-

Section: Orientation Dependencementioning

confidence: 99%

Two‐Dimensional Electron Gas in the n‐Inversion Layer of p‐Type InSb Bicrystals

Herrmann

Kraak

Nachtwei

et al. 1985

“…With this paper a t first we intend to provide a more detailed understanding of the system considered by comparing the theoretical results with t,he experimental ones from Shubnikov-de Haas and cyclotron measurements [G to 8, 10, 131 mainly in the composition region 0. 19 …”

Section: Introductionmentioning

confidence: 99%

Theory for n‐Surface Charge Layers in Hg_1−xCd_xTe MIS Structures

Zöllner

Paasch

Gobsch

et al. 1988

Self Cite

The energy gap of the Hg1−xCdxTe‐system can be controlled by the mole fraction x of Cd. This offers the possibility to use this material as a model system for systematic investigations especially in the narrow‐gap region (corresponding to 0.16 ≦ x ≦ 0.25). The electronic structure, subband occupations, subband energies, and cyclotron masses are calculated for the two‐dimensional electron gas in MIS structures with this material using an approximate self‐consistent method. Both, inversion and accumulation conditions are considered. Comparisons with existing limited theoretical results and with experimental ones a) show the accuracy of the method used and b) allow to interpret the detailed experimental results from Shubnikov‐de Haas and cyclotron measurements available now. Predictions are made on the composition dependence of the electronic structure especially for inversion conditions.

“…The results to be discussed later show that actually a good approximation has been found in this way. For the potential (1) with (16) the lowest eigenvalue is exactly given by (15) and the second one can be determined with a quasi-classical quantization method which has been adapted to potentials of the type (1) [15]. Then…”

Section: Improved Modelmentioning

confidence: 99%

Conditions for the Occurrence of the Electric Quantum Limit in Inversion Layers

Zöllner

Paasch

1989

Self Cite

I n the electric quantum limit (EQL) only the lowest two-dimensional subband of a n inversion layer is populated. Whereas in some materials EQL is observed in others many subband states are populated. An almost analytical description of the inversion layer is derived. It yields conditions for the occurrence of the EQL. An upper limit for the EQL is calculated in dependence on material parameters, interface orientation, and doping concentration. Results are presented and discussed for a series of MIS systems and semiconducting bicrystals. The few available previous theoretical and experimental values for the EQL are well reproduced by the general description.Im elektrischen Quantengrenzfall (EQL) ist lediglich das niedrigste zweidimensionale Subband einer Inversionsschicht besetzt. Wahrend in einigen Substanzen nur der EQL beobachtet wurde, gibt es in anderen auch den Fall mehrerer besetzter Subbander. Es wird eine im wesentlichen analytische Beschreibung der Inversionsschicht abgeleitet. Sie liefert Bedingungen fur das Auftreten des EQL. Eine obere Grenze fur den EQL wird in Abhangigkeit von Materialparametern, der Grenzflachenorientierung und der Dotierung berechnet. Resultate fur eine Reihe von MIS-Systemen und Halbleiterbikristallen werden angegeben und diskutiert. Die wenigen bisher publizierten theoretischen und experimentellen Werte fur die obere Grenze des EQL werden durch die vorgestellte allgemeine Beschreibung sehr gut reproduziert.