21 February 2011 Resonant thermo-tunneling design for ultra-efficient nanostructured solar cells
Author Affiliations +
Abstract
Nanostructured solar cells are touted to lead to super high photo-conversion efficiencies. Nevertheless the inclusion of potential energy fluctuations associated with those structures hinders the smooth vertical transport of photo-generated carriers. We present an innovative energy level engineering design that significantly facilitates the collection of all photo-generated carriers. Using dilute nitride III-V semiconductor quantum wells embedded in a conventional III-V GaAs host, we demonstrate the possibility of achieving a quasi-flat valence band that will ease the smooth transport of holes. The conduction band confinement energies are designed in a way that promotes thermo-tunneling electrons from their potential wells to the conduction band continuum. Energy levels were calculated by including strain and spin-orbit interaction. The calculation of confinement energies was also undertaken. Once confinement energies and potential barrier heights were determined we complemented the theoretical evaluation by calculating carrier escape times via thermionic and tunneling routes at 300 K. Here we demonstrate that an optimized resonant thermo-tunneling design leads to ultra rapid escape. The suggested approach is thus expected to circumvent recombination losses and lead to a substantial carrier collection and efficiency improvements.
© (2011) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
A. Alemu, A. Alemu, A. Freundlich, A. Freundlich, } "Resonant thermo-tunneling design for ultra-efficient nanostructured solar cells", Proc. SPIE 7933, Physics and Simulation of Optoelectronic Devices XIX, 79330S (21 February 2011); doi: 10.1117/12.875252; https://doi.org/10.1117/12.875252
PROCEEDINGS
6 PAGES


SHARE
RELATED CONTENT

Quantum wells for high-efficiency photovoltaics
Proceedings of SPIE (March 14 2016)
Hot-carrier solar cell NEGF-based simulations
Proceedings of SPIE (March 14 2016)
Minibands modeling in strain-balanced InGaAs/GaAs/GaAsP cells
Proceedings of SPIE (February 23 2017)
Low-energy generation in nanostructured Si
Proceedings of SPIE (May 05 2008)
InGaAs/GaAsP quantum wells for hot carrier solar cells
Proceedings of SPIE (February 21 2012)

Back to Top