Quantum cutting in Pr^3+-Yb^3+ codoped chalcohalide glasses for high-efficiency c-Si solar cells

Abstract

Downconversion materials, which can convert one high-energy photon to two low-energy photons, have provided a promising avenue for the enhancement of solar cell efficiency. In this work, the Pr3+-Yb3+ codoped 25GeS2-35Ga2S3-40CsCl chalcohalide glasses were synthesized in a vacuumed silica ampoule by the melting-quenching technique. Under 474 nm excitation, the visible and near-IR emission spectra reveal the energy transfer from Pr3+ to Yb3+ ions, resulting in the intense 1008 nm near-IR emission for the c-Si solar cells. By tuning the excitation laser power, it is determined that one visible photon has been cut into two near-IR photons during the energy transfer process. With the help of an integrated sphere, the real quantum yields of near-IR emissions were calculated. For the 0.2Pr2S3-0.2Yb2S3 (in mol.%) codoped chalcohalide glass, the quantum yield equals 10.8%. Although this efficiency is still low, this result will open a new route to realize the efficient spectral modification of the solar spectrum.

Infrared fibers

“…Despite the extensive research on REI-doped ChGs since the 1990s, there has been only limited success to date [34,37]. Further efforts have been carried out on identifying ChG compositions that enable high doping concentrations [272,273,303] while maintaining low phonon energy for IR emission, rare-earth co-doping schemes [266,304], in addition to reducing the fiber loss by increasing the ChG purity and uniformity [305]. Crystalline Cr 2 : ZnS∕Se nanoparticles have also been introduced into AsS-Se glass systems and fibers for active applications [300][301][302].…”

First down converter multilayers integration in an industrial Si solar cell process

“…2,[14][15][16][17][18][19][20] In that respect, down conversion (DC) answers the thermalization issue by converting high energy photons to a greater number of lower energy photons with energies close to the Si-SC gap. Many systems using a couple of rare earth (RE) ions, such as Pr 3+ -Yb 3+ , [21][22][23] Tb 3+ -Yb 3+ , [24][25][26][27] and Ce 3+ -Yb 3+ , 28,29 have been studied for the DC approach. The major drawbacks of those different developed systems are the use of a non-Si-compatible process due to the nature of the host matrix and/or the low absorption cross section of the RE ions that limits their excitability in the solar spectrum range.…”

Efficient near-infrared downconversion and energy transfer mechanism in Tb^4+-Yb^3+ co-doped NaYF_4 nanoparticles

“…The mismatch between the solar spectrum and the band gap energy of silicon semiconductor limits the photovoltaic conversion efficiency of silicon-based solar cells, because photons with energy lower than the band gap cannot be absorbed, while for photons with energy larger than the band gap, the excess energy is lost by thermalization of hot charge carriers [2][3][4]. Herein, there are many routes to improve the conversion efficiency, and one of them is the downconversion (DC) [5][6][7][8][9][10]. The DC process can convert ultraviolet-visible (UV-Vis) photon (300-600nm) into near-infrared (NIR) photon (~1000nm), which can be efficiently absorbed by silicon-based solar cells [1].…”