@prefix dcat: . @prefix dct: . @prefix foaf: . @prefix vcard: . @prefix xsd: . a dcat:Dataset ; dct:description """ The objective of the present work is to develop luminescent materials with a quantum yield higher than 100% for improving the conversion efficiency of photovoltaic solar cells. The study is focused on rare-earth-doped sulfide-based materials with low phonon energy. The multiplication of photon is firstly studied in rare-earths doped Ga₂S₃-GeS₂-CsCl glasses. It has been demonstrated that one visible photon can be divided into two NIR photons by the rare earth couples Er³⁺/Yb³⁺ou Pr³⁺/Yb³⁺. However, the overall quantum yield measured with an integrating sphere is much lower than 100%. The low quantum yield is attributed to the high concentration of impurities acting as "luminescence killers" and to the charge-transfer absorption of Yb³⁺ which is located in the visible region in sulfides. The rare-earth oxysulfides are then introduced as matrix since the partial substitution of sulfur by oxygen shifts the charge transfer band of Yb³⁺ to the UV region. The oxysulfides with high purity are prepared by combustion method with subsequent sulfuration. The multiplication of photon in the NIR is confirmed in La₂O₂S doped with Pr³⁺/Yb³⁺, Er³⁺,Yb³⁺ and Tb³⁺/Yb³⁺. To the best of our knowledge, it is the first time that quantum yield higher than 100% is directly measured in La₂O₂S : Er³⁺,Yb³⁺. A core-shell structure is designed to sensitize Er3+ in the oxysulfides by Ce³⁺ in the YAG. By homogeneous precipitation with urea, the Y₂O₂S is precipitated on the fine powders of YAG : Ce³⁺. Although the desired structure is not yet obtained due to the diffusion of Er³⁺ into the YAG, further efforts on this subject seem promising to invent spectral convertors with large and intense absorption band. """ ; dct:identifier "NNT: 2012REN1S133" ; dct:issued "2026-05-14T04:18:57.524109"^^xsd:dateTime ; dct:language "fr" ; dct:modified "2026-05-14T04:18:57.524115"^^xsd:dateTime ; dct:publisher ; dct:title "Luminescent glasses and ceramics for improving the efficiency of photovoltaic solar cells" ; dcat:contactPoint [ a vcard:Organization ; vcard:fn "CCSD" ] ; dcat:distribution ; dcat:keyword "cellules-solaires-photovoltaiques", "ceramiques-luminescentes", "chimmatechemical-sciencesmaterial-chemistry", "infoeu-reposemanticsdoctoralthesis", "photoluminescence", "photovoltaic-solar-cells", "rare-earths", "rendement-quantique", "spectroscopie", "spectrum-analysis", "sulphides-glasses", "terre-rare", "theses", "verres-de-sulfure", "ytterbium" ; dcat:landingPage . a dcat:Distribution ; dct:format "HTML" ; dct:issued "2026-05-14T04:18:57.585329"^^xsd:dateTime ; dct:modified "2026-05-14T04:18:57.495789"^^xsd:dateTime ; dct:title "Luminescent glasses and ceramics for improving the efficiency of photovoltaic solar cells" ; dcat:accessURL . a foaf:Agent ; foaf:name "test_moissonnage_selune" . a foaf:Document .