Enhancing Photovoltaic Performance Using Broadband Luminescent Down-Shifting by Combining Multiple Species of Eu-Doped Silicate Phosphors

Abstract

This paper demonstrates the application of a broadband luminescent downshifting (LDS) layer with multiple species of europium (Eu)-doped silicate phosphors using spin-on film technique to enhance the photovoltaic efficiency of crystalline silicon solar cells. The surface morphology of the deposited layer was examined using a scanning electron microscope (SEM). The chemical composition of the Eu-doped silicate phosphors was analyzed using energy-dispersive X-ray spectroscopy (EDS). The fluorescence emission of the Eu-doped silicate phosphors was characterized using photoluminescence (PL) measurements at room temperature. We also compared the optical reflectance and external quantum efficiency (EQE) response of cells with combinations of various Eu-doped phosphors species. The cell coated with two species of Eu-doped phosphors achieved a conversion efficiency enhancement (∆η) of 19.39%, far exceeding the ∆η = 15.08% of the cell with one species of Eu-doped phosphors and the ∆η = 8.51% of the reference cell with the same silicate layer without Eu-doped phosphors.

Lanthanide-based downshifting layers tested in a solar car race

“…Several studies showing improvements in solar cells performance with distinct LDS phosphors were reported, such as organic dyes 9,10 , quantum dots (QDs) 9 , and lanthanide ions (Ln 3+ ) coordination complexes 6,7,[9][10][11][12][13][14][15][16][17][18] . The reasons for the wide utilization of Ln 3+ complexes (europium, Eu 3+ , and terbium, Tb 3+ ) are related to their strong emission and photostability and also the emission profile in the visible spectral range, which overlaps the absorption of c-Si solar cells.…”

Improved photovoltaic performance of monocrystalline silicon solar cell through luminescent down‐converting Gd2O2S:Tb3+ phosphor

“…In a down‐conversion (DC) process, a high‐energy incident photon is absorbed by the DC phosphors and re‐emitted as two or more lower energy photons at wavelengths where the silicon solar cells exhibit a strong spectral response . A number of researchers have shown that there is significant enhancement in conversion efficiency of solar PV devices by integrating a down‐converting or luminescent down‐shifting (LDS) layer on the top surface of c‐Si solar cells …”

Enhancing Photovoltaic Performance of GaAs Single-Junction Solar Cells by Applying a Spectral Conversion Layer Containing Eu-Doped and Yb/Er-Doped Phosphors

“…Considerable effort has gone into the creation of high-efficiency single-junction solar cells by overcoming the conversion efficiency limit. This has led to the development of multiple bandgap tandem cells [7,8,9,10,11], intermediate bandgap cells [12,13,14], down-conversion (DC) cells [15,16,17,18,19,20], up-conversion (UC) cells [21,22,23,24,25,26], and luminescent downshifting (LDS) cells [27,28,29,30]. In recent years, luminescent-phosphors materials for DC, UC, and LDS, which are capable of converting a broad spectrum of light into photons of particular wavelengths, have been synthesized and used to minimize the losses in the photovoltaic device energy conversion process.…”