Resonant tunneling in the ZnO/Zn1−xCdxO/ZnO double barrier structures: Theoretical study

• Calculations of I–V characteristics of the ZnO/ZnCdO/ZnO structures were done.
• Polarization field leads to blueshift of resonant energy.
• Tunneling current in ZnO/ZnCdO/ZnO depends on well width and barrier thickness.

Numerical simulations of Zn1−xCdxO/ZnO-based resonant tunneling diode structures are presented, employing the transfer matrix formalism and the Tsu–Esaki model. The factors influencing on the effective electron mass of the two-dimensional electron gas in the Zn1−xCdxO/ZnO heterointerface – a conduction band nonparabolicity, a quantum confinement and a polaron effect – were analyzed and evaluated. The simulated current–voltage characteristics show a strong dependence on a well width, a barrier thickness and an internal electric field induced by a spontaneous and a piezoelectric polarization.