Premium
Donor Centers Involved into the Quantum Cutting in Ytterbium‐Doped Scheelite‐Like Crystals
Author(s) -
Subbotin Kirill A.,
Titov Anatolii I.,
Lis Denis A.,
Sani Elisa,
Smirnov Valerii A.,
Alimov Olimkhon K.,
Zharikov Evgenii V.,
Shcherbakov Ivan A.
Publication year - 2020
Publication title -
physica status solidi (a)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.532
H-Index - 104
eISSN - 1862-6319
pISSN - 1862-6300
DOI - 10.1002/pssa.201900659
Subject(s) - scheelite , tungstate , molybdate , ytterbium , doping , materials science , impurity , ion , luminescence , exciton , tungsten , optoelectronics , chemistry , condensed matter physics , physics , metallurgy , organic chemistry
Yb‐doped Scheelite‐like molybdate and tungstate single crystals are promising quantum‐cutting materials. The cooperative downconversion from donor centers to Yb ions occurs in heavily Yb‐doped crystals of this family. This phenomenon can substantially raise the efficiency of crystalline silicon photovoltaic cells. However, the nature of donor centers is still unknown. Herein, several versions of this nature are tested and discussed: Yb 3+ ion (its high‐energy charge transfer states); Yb 2+ ion; self‐trapped exciton at molybdate/tungstate complex; color centers based on oxygen vacancies; accidental impurities. To test these assumptions, a series of Scheelite‐like molybdate and tungstate single crystals (CaMoO 4 , CaWO 4 , NaLa(MoO 4 ) 2 , NaGd(MoO 4 ) 2 , NaGd(WO 4 ) 2 , and NaY 1− x Gd x (WO 4 ) 2 ) are grown, both undoped and doped with different Yb‐concentrations. The complex spectroscopic investigations of these crystals are performed. As a result of the studies, three versions, self‐trapped excitons at [MoO 4 ]/[WO 4 ] complexes, color centers at oxygen vacancies, and accidental impurities, coming into the crystals with MoO 3 , are rejected. The applicability of the other versions should be refined.