Ytterbium sensitization in KY 3F 10: Pr 3+, Yb 3+ for silicon solar cells efficiency enhancement

• Published in: Optical materials Vol. 33; no. 7; pp. 1028 - 1031
• Main Authors: Serrano, D., Braud, A., Doualan, J.-L., Camy, P., Benayad, A., Ménard, V., Moncorgé, R.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 2011
• Subjects: Downconversion; KY 3F 10; Quantum cutting; Rare earth; Solar cell; Solar cell; Downconversion; KY 3F 10; Rare earth; Quantum cutting
• ISSN: 0925-3467; 1873-1252
• DOI: 10.1016/j.optmat.2010.07.023

The codoping of KY 3F 10 with Pr 3+ and Yb 3+ ions is investigated as a possible quantum cutting system to enhance solar cells efficiency. For one visible photon absorbed by Pr ions, two ytterbium ions are expected to be excited by two consecutive energy transfers. The subsequent emission of two infrared photons reduces thus the thermalization losses usually observed in Si solar cells. Emission spectra and lifetime decays in KY 3F 10 doped with 0.5% Pr 3+ and codoped with 0%, 1%, 10% and 20% Yb 3+ show an increase of the energy transfer efficiency from Pr 3+ to Yb 3+ with the Yb 3+ concentration. For the first Pr 3+ to Yb 3+ energy transfer, an efficiency close to 100% is achieved in KY 3F 10: 0.5%Pr 3+, 20%Yb 3+. However, this promising result faces challenging issues since an increase in Yb concentration induces energy migration between Yb 3+ ions which impairs the Yb 3+ luminescence.