Transport Phenomena in Two-Dimensional Structures with Quantum Dots

• Authors: J. Požela
• Languages of publication: EN

Abstracts

EN

A model that explains the unusual characteristics of the AlGaAs/GaAs modulation-doped field-effect transistor (MODFET) with InAs quantum dots incorporated in the GaAs channel is presented. It is shown that the negative charge of electrons confined in quantum dots decreases the threshold gate-drain voltage at which the channel is fully depleted. This provides an impact ionization of quantum dots at a low drain voltage. Because of the quantum dot ionization, the quantum dot MODFET transconductance becomes large and negative. The increased transconductance, due to the additional doping of the GaAs and InAs channels by impurities, exceeds 10^3 mS/mm. It is shown that the insertion of InAs quantum well with quantum dots into the GaAs quantum well increases the electron maximum drift velocity up to 10^8 cm/s, and consequently, quantum dot MODFET current gain cut-off frequency up to few hundred gigahertz.

Keywords

EN

73.63.Hs; 73.63.Kv; 85.35.Be; 85.30.Tv

Discipline

• 85.30.Tv: Field effect devices
• 85.35.Be: Quantum well devices (quantum dots, quantum wires, etc.)
• 73.63.Hs: Quantum wells
• 73.63.Kv: Quantum dots

• Publisher: Institute of Physics, Polish Academy of Sciences
• Journal: Acta Physica Polonica A
• Year: 2005
• Volume: 107
• Issue: 1
• Pages: 118-127

Dates

published

2005-01

received

2004-08-22

Contributors

author

J. Požela

• Semiconductor Physics Institute, A. Goštauto 11, Vilnius 01108, Lithuania

References

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Identifiers

DOI

10.12693/APhysPolA.107.118