Upconverter solar cells: materials and applications

Abstract

Spectral conversion of sunlight is a promising route to reduce spectral mismatch losses that are responsible for the major part of the efficiency losses in solar cells. Both upconversion and downconversion materials are presently explored. In an upconversion process, photons with an energy lower than the band gap of the solar cell are converted to higher energy photons. These higher photons are directed back to the solar cell and absorbed, thus increasing the efficiency. Different types of upconverter materials are investigated, based on luminescent ions or organic molecules. Proof of principle experiments with lanthanide ion based upconverters have indicated that the benefit of an upconversion layer is limited by the high light intensities needed to reach high upconversion quantum efficiencies. To address this limitation, upconverter materials may be combined with quantum dots or plasmonic particles to enhance the upconversion efficiency and improve the feasibility of applying upconverters in commercial solar cells.

Photochemical upconversion: present status and prospects for its application to solar energy conversion

“…sentially complementary approaches: 6,10 Firstly, the application of lanthanoid cations (mostly Erbium and Ytterbium) in a solid-state matrix, 11 making use of their discrete and longlived atomic states that can facilitate absorption of multiple photons, followed by upconverted luminescence. The rareearth materials absorb in the infrared region of the solar spectrum and lanthanoid upconversion (L-UC) is thus most interesting for application to c-Si solar cells [12][13][14] .…”

Photon upconversion sensitized by a Ru(II)-pyrenyl chromophore

“…These two observations together indicate complete transfer of absorbed photons from the Ru(py-phen) 2+ 3 triplet to the sensitized anthryl triplets in the chromophore mixture. Thus, these laser flash photolysis experiments demonstrate that the selective excitation of Ru(py-phen) 2+ 3 results in the T 1 → T n absorption spectrum characteristic of 3 An * in the mixed solution, verifying that the MLCT photoluminescence quenching proceeds exclusively through TTET.…”

“…Since its inception, photon UC has been recognized as a viable technology for exceeding the ShockleyQueisser limit in photovoltaics by creating a mechanism through which sub-bandgap photons can be captured and converted into photocurrent [3][4][5][6][7][8][9][10][11]. Apart from that, a variety of potential applications for TTA upconversion have been proposed in the literature, e.g.…”

Model studies on the separation of Ca2+ and Nd3+ ions using ethylenediaminetetraacetic acid

“…There has been a considerable increase in applications of RE due to their desirable chemical, catalytic, electrical, magnetic and optical properties. These applications widely range from polishing agents [1,2] through lasers [3,4] and magnets [5,6] or batteries [7] to modern technologies such as those of solar panels [8,9], high-temperature superconductors [10] and plasma display panels [11,12].…”