INVESTIGATIONS OF THE NEGATIVE DIFFERENTIAL CONDUCTIVITY AND CURRENT BISTABILITY IN DOUBLE BARRIER n+ GaAs/(AlGa)As/GaAs/(AlGa)As/n+ GaAs RESONANT TUNNELLING DEVICES USING HIGH MAGNETIC FIELDS

C.A. PAYLING; E. ALVES; L. EAVES; T.J. FOSTER; M. HENINI; O.H. HUGHES; P.E. SIMMONDS; J.C. PORTAL; G. HILL; M.A. PATE

doi:doi:10.1051/jphyscol:1987563

Numéro		J. Phys. Colloques Volume 48, Numéro C5, Novembre 1987 3rd International Conference on Modulated Semiconductor Structures


Page(s)		C5-289 - C5-292
DOI		https://doi.org/10.1051/jphyscol:1987563

3rd International Conference on Modulated Semiconductor Structures

J. Phys. Colloques 48 (1987) C5-289-C5-292
DOI: 10.1051/jphyscol:1987563

INVESTIGATIONS OF THE NEGATIVE DIFFERENTIAL CONDUCTIVITY AND CURRENT BISTABILITY IN DOUBLE BARRIER n⁺ GaAs/(AlGa)As/GaAs/(AlGa)As/n⁺ GaAs RESONANT TUNNELLING DEVICES USING HIGH MAGNETIC FIELDS

C.A. PAYLING¹, E. ALVES¹, L. EAVES¹, T.J. FOSTER¹, M. HENINI¹, O.H. HUGHES¹, P.E. SIMMONDS¹, J.C. PORTAL², G. HILL³ et M.A. PATE³

¹ Department of Physics, University of Nottingham, GB-Nottingham NG7 2RD, Great-Britain
² SNCI-CNRS, Grenoble, F-38042 Cedex, and LPS, I.N.S.A., Toulouse, F-31077 Cedex, France
³ Department of Electronic Engineering, University of Sheffield, GB-Sheffield, S1 3JD, Great-Britain

Résumé
Conductivité négative différentielle (CND) et bistabilité en courant dans une structure tunnel résonnante ont été étudiées par l'effet oscillatoire dans le courant magnétotunnel avec J||B. Les mesures montrent que la bistabilité est associée avec l'accumulation et l'éjection de charge négative du puits. CND associé avec la deuxième sous-bande du puits est observée à plus grand voltage (~ 1 V). Les magnéto-oscillations indiquent la présence du tunnel séquentiel à cette région.

Abstract
Negative differential conductivity (NDC) and current bistability in a resonant tunnelling device are investigated by examining the oscillatory structure in the magnetotunnelling current for J ||B. The data support the conclusion that bistability is associated with build-up and ejection of negative space charge from the well. The charge density of 2D electrons in the contact accumulation layer is measured directly. NDC due to tunnelling into the second sub-band of the well is observed at high bias (~ 1 V). The associated magneto-oscillations indicate the presence of sequential tunnelling in this region of the I(V) curves.