Room-temperature current-voltage characteristics in AlAs-GaAs-AlAs double-barrier structures: Calculations using a bond-orbital model

This paper reports the current-voltage characteristics of the AlAs-GaAs-AlA s double-barrier structures (DBS's) grown along the [001] and [111] directi ons at room temperature, within a fourth-neighbor bond-orbital model. We de monstrate that at room temperature the resonant-tunneling current is domina ted by the L-valley electrons instead of Gamma-valley electrons for an AlAs -GaAs-AlAs DBS with barrier widths of similar to 3 nm or more. We also demo nstrate that at room temperature not only the peak current but also the pea k-to-valley ratio can be significantly improved by orienting the materials along the [111] direction, due to the Gamma- and L-point orientation effect s. [S0163-1829(99)03727-3].