Numerical simulation of tunnel diodes and multi-junction solar cells

In order to connect individual subcells in monolithically grown multi-junction solar cells Esaki interband tunnel diodes are widely used. In this work, numerical simulations of an isolated III-V Esaki tunnel diode and of a dual-junction solar cell are presented. With a tunnel model, which takes into account the full nonlocality of the tunneling process, a good agreement between measured and simulated IV curve of a GaAs tunnel diode could be achieved. Using this model, the EQE and the IV curve of a complete dual-junction solar cell including tunnel diode was simulated. The model is applied to calculate the current-matching condition of the dual-junction cell.