Recent investigations of electroluminescence and current instabilities of tunneling silicon MOS diodes show that a dense 2D electron layer, screening an electrical field, and an additional 2D hole layer are formed at a silicon surface under tunneling injection of holes into a selforganized hole quantum well [1,2]. The recombination radiation line (S-line) of 2D electrons and 2D injected holes is observed. The electron polarization attraction of a hole to the 2D electron layer and an electrical field of additional electrons in the electron quantum well cause the formation of the hole quantum well. Tunneling into 2D states of the hole quantum well is much more effective than tunneling into 3D states of the valence band minimum.

The recombination radiation line (S-line) of 2D holes and 2D injected electrons is observed also in electroluminescence spectra of tunneling silicon MOS diodes with a p-type substrate ?3?. In this case the selforganized electron quantum well in presence of an electrical field in the substrate forms an additional potential barrier. The transparency of the additional barrier depends on the electrical field in the substrate, on the density of 2D electrons, on the temperature and can be modulated by the electrical field in the substrate. This gives an opportunity of a strong and fast modulation of the 2D electron density and the S-line intensity. A possible realization of a tunneling ballistic transistor (tullistor) by use of this modulation is discussed [2,3]. Semiconductor heterostructures with proper potential barriers and gates can be used for fabrication of the tullistor as well as silicon MOS structures. A highly doped ntype semiconductor with a thin undoped layer serves as the substrate. The base of the tullistor is the 2D hole layer, the emitter is the gate and the collector is the highly doped part of the substrate. The tullistor at a proper gate potential, applied between the base and the gate, and a proper substrate potential, applied between the gate and the substrate, represents a transistor with a ballistic current in the undoped layer. At the substrate potential equal to zero the tullistor represents an effective light emitter with 2D holes and 2D injected electrons. A high frequency modulation of the light intensity is produced by a high frequency change of the substrate potential. If the Fermi level in the gate is a little bit lower than the lowest electron quantum level, the tullistor can be used as a photodetector. A simple theory of the tullistor is given, and the tunneling currents of electrons and holes are calculated. The operating temperature of the tullistor is estimated as (1 - 100) K.

In the case of a small size of the gate, when a quantum confinement for electrons is realized, the tullistor can represent a light emittig quantum dot or a quantum photodetector and can be used as an element in high speed integrated optoelectronic devices for generation and detection of light signals.

1. P.D.Altukhov, A.G.Bulgakov, G.V.Ivanov, E.G.Kuzminov, Sol. St. Commun.103, 103 (1997).
2. P.D.Altukhov, G.V.Ivanov, E.G.Kuzminov, Solid State Electronics 42, 1657 (1998).
3. P.D.Altukhov, E.G.Kuzminov, Phys. Stat. Sol. (b) 221, 439 (2000).