Tunneling and magneto-tunnelling effects in n+GaAs/(AlGa)As/n-GaAs/n+GaAs devices

Oscillatory stuctures recently reported by Hickmott et al. (1984) in the I-V characteristics of n + GaAs/(AlGa)As/n - GaAs/n + GaAs tunnelling devices are observed at zero magnetic field and temperatures up to 50K, demonstrating that neutralisation of donors by magnetic freeze-out in the n - GaAs layer is not required to observe the structure.