Strong effect of the wavelength of light on quantum oscillations of the photocurrent and their resonant tunneling nature in $p{-}i{-}n$ GaAs/AlAs heterostructures

The strong effect of the wavelength of incident light $\lambda$ on the fraction of the oscillatory component of the photocurrent in $p{-}i{-}n$ GaAs/AlAs heterostructures has been revealed. The effect has been explained within the extended “resonant tunneling” model of the origin of oscillations taking also into account the dependence of the light absorption depth in the heterostructure on the wavelength $\lambda$. The behavior of photo-oscillations in the magnetic field appears to be similar to the behavior of tunneling resonances in $n{-}i{-}n$ heterostructures with wide quantum wells and has confirmed both our interpretation of the effect of the wavelength on the relative contribution of the oscillatory component to the photocurrent and the applicability of our model of oscillations.