Theoretical investigation of the carrier escape in InGaN quantum well solar cells

This theoretical work analyzes the photo-generation and the escape of carrier in InGaN/GaN core-shell nanowires. Our electronic transport model considers quantum behaviors such as confinement, tunneling, electron-phonon scattering and electron-photon interactions. The large lattice mismatch between InN and GaN requires the use of multiple quantum well design, in which either In content or well thickness is limited. Since thick GaN barriers are required in these stressed devices, we show that tunneling has a negligible impact on carrier escape, which is mostly achieved by the phonon absorption. This thermionic escape strongly depends on the quantum confinement. Our conclusions demonstrate that a thick quantum well with a low In content, in which the confinement is moderate, is more efficient.