Quantum tunneling design for ultra-fast photogenerated carrier collection in p-i-n III–V quantum confined solar cells

摘要

III–V semiconductor based quantum structures displaying quasi-3D holes and resonant tunneling alignment at the conduction band incorporated in the intrinsic region of p-i-n GaAs solar cells are investigated. The choices of the material system and energy band design are tuned towards facilitating the collection of all photo-generated carriers while minimizing recombination losses. Ultra-fast carrier transfer times in the order of 10⁻¹⁵ s are obtained indicating the possibility of extracting carriers before slower recombination losses. The designs are expected to minimize radiative recombination. The faster spatial separation between tunneling electrons and quasi-3D holes under electric field is expected to play a key role in reducing carrier recombination. Such carefully engineered quantum confined material system optimized for improved collection of photo-generated carriers is anticipated to usher efficiencies in the vicinity of ideal limits.