Barrier potential design criteria in multiple-quantum-well-based solar-cell structures

Abstract
The barrier potential design criteria in multiple-quantum-well (MQW) -based solar-cell structures is reported for the purpose of achieving maximum efficiency. The time-dependent short-circuit current density at the collector side of various MQW solar-cell structures under resonant condition was numerically calculated using the time-dependent Schrödinger equation. The energy efficiency of solar cells based on InAs/GayIn1−yAs and GaAs/AlxGa1−xAs MQW structures were compared when carriers are excited at a particular solar-energy band. Using InAs/GayIn1−yAs MQW structures it is found that a maximum energy efficiency can be achieved if the structure is designed with barrier potential of about 450 meV. The efficiency is found to decline linearly as the barrier potential increases for GaAs/AlxGa1−xAs MQW-structure-based solar cells.