PROJECT TITLE :

Strong Internal and External Luminescence as Solar Cells Approach the Shockley–Queisser Limit

ABSTRACT:

Absorbed daylight in a very solar cell produces electrons and holes. But, at the open-circuit condition, the carriers have no place to travel. They build up in density, and ideally, they emit external luminescence that exactly balances the incoming sunlight. Any extra nonradiative recombination impairs the carrier density buildup, limiting the open-circuit voltage. At open circuit, economical external luminescence is an indicator of low internal optical losses. Thus, economical external luminescence is, counterintuitively, a necessity for approaching the Shockley–Queisser (SQ) potency limit. A great solar cell also needs to be a great light-emitting diode. Due to the slim escape cone for light, economical external emission needs repeated attempts and demands an enclosed luminescence potency 90%.