Rigorous simulation of InAlGaAs-InGaAs bulk and quantum well interband tunnel junctions for multi-junction solar cells

In this paper, rigorous numerical simulations of direct and phonon-assisted tunneling currents in InAlGaAs-InGaAs bulk and quantum well interband tunnel heterojunctions with applications in high-efficiency multi-junction solar cells are presented. The quantum-kinetic model reproduces experimentally observed features in the current-voltage characteristics of the devices, such as the pronounced current enhancement in the quantum well junction as compared to the bulk junction, and reveals at the same time the impact of quasi-bound states, electric fields and electron-phonon scattering on the interband tunneling current. Absorption losses induced by the quantum wells are assessed within the same theoretical framework and thus in consistency with the evaluation of the electronic properties.