Estimating the performance of solar cells with luminescent down-shifting layers

Abstract

Technological developments for improving the performance of conventional solar cells have become a topic of great interest in recent years. For instance, solar concentrators, new anti-reflective coatings, and Luminescent Down-Shifting Layers (LDS), among different techniques have been used in the past. The latter is an attractive option because an LDS layer has the property of increasing the photon flux density in the appropriate wavelength range on top of a cell device with the possibility of increasing the photo-current density. Then, in this work we focus on the development of a theoretical model to determine the cell´s illumination current density, considering the modified solar spectrum, and taking in account the modified spectral reflectance and transmittance at the upper layers when an optimized LDS layer is inserted on a solar cell. The correct selection of such a layer for a specific solar cell would increase its performance due to the enhanced photon density in the absorption region for which the solar cell has the highest quantum efficiency. As an example, it is shown that a Lu3Al5O12:Ce3+ layer on top of a CdTe solar cell might cause an efficiency increase of around 21%.

AgIn5S8/ZnS Quantum Dots for Luminescent Down-Shifting and Antireflective Layer in Enhancing Photovoltaic Performance

“…Since first reported by Hovel et al in 1979, LDS layers have been considered as one of the effective strategies to improve the efficiency of solar cells. So far, rare-earth doped phosphors, − organic luminescent dyes, , and quantum dots (QDs) ,− have been reported as LDS materials. Among them, colloidal semiconductor QDs have attracted much attention due to their outstanding photoluminescence ,, and tunable emission wavelength by controlling their size. , Ternary I–III–VI semiconductor QDs, e.g., Ag- and Cu-based, play a pivotal role as an alternative to environmentally unfriendly Cd- and Pb-based QDs in optoelectronic devices.…”