Abstract: Luminescent materials and the use of such materials in anti-counterfeiting, inventory, photovoltaic, and other applications are described herein. In one embodiment, a luminescent material has the formula: [AaBbXxX?x?X?x?][dopants], wherein A is selected from at least one of elements of Group IA; B is selected from at least one of elements of Group VA, elements of Group IB, elements of Group IIB, elements of Group IIIB, elements of Group IVB, and elements of Group VB; X, X?, and X? are independently selected from at least one of elements of Group VIIB; the dopants include electron acceptors and electron donors; a is in the range of 1 to 9; b is in the range of 1 to 5; and x, x?, and x? have a sum in the range of 1 to 9. The luminescent material exhibits photoluminescence having: (a) a quantum efficiency of at least 20 percent; (b) a spectral width no greater than 100 nm at Full Width at Half Maximum; and (c) a peak emission wavelength in the near infrared range.

Abstract: Apparatus, system, and method to authenticate and identify objects using nanoparticles are described herein. In one embodiment, a computer-readable storage medium includes executable code to: (1) derive an index based on an authentication image of a marking; (2) select a reference image of the marking based on the index; (3) compare the authentication image with the reference image to determine whether the authentication image matches the reference image; and (4) produce an indication of authenticity based on whether the authentication image matches the reference image.

Abstract: Described herein are solar modules including spectral concentrators. In one embodiment, a solar module includes an active layer including a set of photovoltaic cells. The solar module also includes a spectral concentrator optically coupled to the active layer and including a luminescent material that exhibits photoluminescence in response to incident solar radiation. The photoluminescence has: (a) a quantum efficiency of at least 30 percent; (b) a spectral width no greater than 100 nm at Full Width at Half Maximum; and (c) a peak emission wavelength in the near infrared range.

Abstract: Nanostructured materials and photovoltaic devices including nanostructured materials are described. In one embodiment, a nanostructured material includes: (a) a first nano-network formed from a first set of nanoparticles; and (b) a second nano-network coupled to the first nano-network and formed from a second set of nanoparticles. At least one of the first set of nanoparticles and the second set of nanoparticles are formed from an indirect bandgap material. The nanostructured material is configured to absorb light to produce a first type of charge carrier that is transported in the first nano-network and a second type of charge carrier that is transported in the second nano-network. The nanostructured material has an absorption coefficient that is at least 103 cm?1 within a range of wavelengths from about 400 nm to about 700 nm.

Abstract: The invention relates to a quantum dot. The quantum dot comprises a core including a semiconductor material Y selected from the group consisting of Si and Ge. The quantum dot also comprises a shell surrounding the core. The quantum dot is substantially defect free such that the quantum dot exhibits photoluminescence with a quantum efficiency that is greater than 10 percent.

Abstract: The invention relates to a quantum dot. The quantum dot comprises a core including a semiconductor material Y selected from the group consisting of Si and Ge. The quantum dot also comprises a shell surrounding the core. The quantum dot is substantially defect free such that the quantum dot exhibits photoluminescence with a quantum efficiency that is greater than 10 percent.

Abstract: The invention relates to an optical device. The optical device comprises a waveguide core and a nanocomposite material optically coupled to the waveguide core. The nanocomposite material includes a plurality of quantum dots. The nanocomposite material has a nonlinear index of refraction ? that is at least 10?9 cm2/W when irradiated with an activation light having a wavelength ? between approximately 3×10?5 cm and 2×10?4 cm.

Abstract: The invention provides “engineered” nonlinear nanocomposite materials with an extremely large ?(3) and fast temporal response along with optical properties that can be precisely tuned to satisfy the requirements of a particular application (e.g., optical, thermal, mechanical, etc.). In particular, the magnitude of the linear and nonlinear index of refraction can be adjusted substantially independently of the absorption spectrum of the material. In addition, the optical characteristics can be engineered substantially independently from the mechanical and chemical characteristics, providing exceptional performance and flexibility in terms of device-incorporation and process-stability.

Abstract: The invention relates to an optical device. The optical device comprises a waveguide core and a nanocomposite material optically coupled to the waveguide core. The nanocomposite material includes a plurality of quantum dots. The nanocomposite material has a nonlinear index of refraction ? that is at least 10?9 cm2/W when irradiated with an activation light having a wavelength ? between approximately 3×10?5 cm and 2×10?4 cm.

Abstract: The invention relates to an optical device. The optical device comprises a waveguide core and a nanocomposite material optically coupled to the waveguide core. The nanocomposite material includes a plurality of quantum dots. The nanocomposite material has a nonlinear index of refraction &ggr; that is at least 10−9 cm2/W when irradiated with an activation light having a wavelength &lgr; between approximately 3×10−5 cm and 2×10−4 cm.

Abstract: The invention relates to a method of forming a quantum dot. A particle that includes a semiconductor material Y selected from the group consisting of Si and Ge is provided. Sound energy and light energy is applied to the particle to form a quantum dot. The quantum dot exhibits photoluminescence with a quantum efficiency that is greater than 10 percent. The quantum dot includes a core, and the core includes Y.

Abstract: The invention relates to a nanocomposite material. The nanocomposite material comprises a matrix material and a plurality of quantum dots dispersed in the matrix material. The nanocomposite material has a nonlinear index of refraction &ggr; that is at least 10−9 cm2/W when irradiated with light having a wavelength &lgr; between approximately 3×10−5 cm and 2×10−4 cm.