Abstract: The invention relates to a heterostructure including a first region (R1) made of a first n-doped semiconductor material, a second region (R2) made of a second p-doped semiconductor material and, between said first and second regions, a type-II superlattice (SR) made up of an alternation of layers (C1, C2) of a third and fourth semiconductor material, said layers being thin enough for the carriers to be displaced inside said superlattice, forming at least one electron mini-band (MBe) and one hole mini-band (MBh), the interfaces between the first region and the superlattice, between the layers of the superlattice and between the superlattice and the second region being mutually parallel. The invention also relates to a photovoltaic cell including such a heterostructure as an active element. The invention further relates to a solar panel including a combination of such photovoltaic cells.

Abstract: A method for measurement of relative fluorescence quantum efficiency of a dye, including: a) for at least two different concentrations of the dye in solution in a solvent, exciting the dye with electromagnetic radiation and measuring the photoluminescence of the dye that has been excited by the radiation and of the signal transmitted through the cell containing the dye; b) comparing the data measured with the photoluminescence and transmission data of a reference dye; and c) calculating the relative fluorescence quantum efficiency of the dye.

Abstract: Luminescent material consisting of nanocrystals comprising a core surrounded by a shell, said core consisting of a nanocrystal of semiconductor of formula AB in which A represents a metal or a metalloid in oxidation state (II) and B represents a chemical element in oxidation state (VI), and said shell consisting of a ZnSe layer whose surface is provided with an organic passivation layer consisting of at least one primary amine combined with at least one phosphine oxide and/or phosphine selenide compound. The invention relates in particular to nanocrystals with a CdSe core, these being covered by a ZnSe shell. The invention furthermore relates to a method of preparing these materials.

Abstract: Luminescent material consisting of nanocrystals comprising a core surrounded by a shell, said core consisting of a nanocrystal of semiconductor of formula AB in which A represents a metal or a metalloid in oxidation state (II) and B represents a chemical element in oxidation state (VI), and said shell consisting of a ZnSe layer whose surface is provided with an organic passivation layer consisting of at least one primary amine combined with at least one phosphine oxide and/or phosphine selenide compound.