Abstract: The invention relates to a core-alloyed shell semiconductor nanocrystal comprising: (i) a core of a semiconductor material having a selected band gap energy; (ii) a core-overcoating shell consisting of one or more layers comprised of an alloy of the said semiconductor of (i) and a second semiconductor; (iii) and an outer organic ligand layer, provided that the core semiconductor material is not HgTe. In certain embodiments, the core semiconductor material is PbSe and the alloy shell semiconductor material has the PbSexS1-x structure; or the core semiconductor material is CdTe and the alloy shell semiconductor material has either the CdTexSe1-x or CdTexS1-x structure.

Abstract: A method is provided for producing semiconductor nanoparticles comprising: (i) dissolving a semiconductor compound or mixture of semiconductor compounds in a solution; (ii) generating spray droplets of the resulting solution of semiconductor compound(s); (iii) vaporizing the solvent of said spray droplets, consequently producing a stream of unsupported semiconductor nanoparticles; and (iv) collecting said unsupported semiconductor nanoparticles on a support.

Abstract: The invention relates to a core-alloyed shell semiconductor nanocrystal comprising: (i) a core of a semiconductor material having a selected band gap energy; (ii) a core-overcoating shell consisting of one or more layers comprised of an alloy of the said semiconductor of (i) and a second semiconductor; (iii) and an outer organic ligand layer, provided that the core semiconductor material is not HgTe. In certain embodiments, the core semiconductor material is PbSe and the alloy shell semiconductor material has the PbSexS1-x structure; or the core semiconductor material is CdTe and the alloy shell semiconductor material has either the CdTexSe1-x or CdTexS1-x structure.

Abstract: The present invention relates to photovoltaic cells comprising group IV-VI semiconductor nanocrystals as photoactive components. In particular, these nanocrystals are of core-shell or core-alloyed shell configuration, each comprising a core of a first group IV-VI semiconductor material having a selected band gap energy, and either a core-overcoating shell consisting of a second group IV-VI semiconductor material or a core-overcoating alloyed shell consisting of an alloy of said first group IV-VI semiconductor material and a second group IV-VI semiconductor material, respectively.

Abstract: A passive Q-switch for a laser system, and a method for its production. The laser is operative at near infrared wavelength region, including the eye-safe region. The Q-switch includes a saturable absorber based on IV-VI semiconductor nanocrystals (NCs), embedded in a polymer matrix. The NCs preferably include lead selenide, lead sulfide, or lead selenide sulfide. The NCs may be surface passivated, and may feature a PbSe/PbS core-shell configuration.

Abstract: The invention relates to a core-alloyed shell semiconductor nanocrystal comprising: (i) a core of a semiconductor material having a selected band gap energy; (ii) a core-overcoating shell consisting of one or more layers comprised of an alloy of the said semiconductor of (i) and a second semiconductor; (iii) and an outer organic ligand layer, provided that the core semiconductor material is not HgTe. Preferably, the core semiconductor material is PbSe and the alloy shell semiconductor material has the PbSexS1-x structure.

Abstract: A passive Q-switch for a laser system, and a method for its production. The laser is operative at near infrared wavelength region, including the eye-safe region. The Q-switch includes a saturable absorber based on IV-VI semiconductor nanocrystals (NCs), embedded in a polymer matrix. The NCs preferably include lead selenide, lead sulfide, or lead selenide sulfide. The NCs may be surface passivated, and may feature a PbSe/PbS core-shell configuration.

Abstract: A passive Q-switch for a laser system, and a method for its production. The laser is operative at near infrared wavelength region, including the eye-safe region. The Q-switch includes a saturable absorber based on IV-VI semiconductor nanocrystals (NCs), embedded in a polymer matrix. The NCs preferably include lead selenide, lead sulfide, or lead selenide sulfide. The NCs may be surface passivated, and may feature a PbSe/PbS core-shell configuration.