High density vertically aligned Porous Silicon NanoWires (PSiNWs) were fabricated on silicon substrate using metal assisted chemical etching process. A linear dependency of nanowire length to the etching time was obtained and the change in the growth rate of PSiNWs by increasing etching durations was shown. A typical 2D bright-field TEM image used for volume reconstruction of the sample shows the pores size varying from 10 to 50 nm. Furthermore, reflectivity measurements show that the 35% reflectivity of the starting silicon wafer drops to 0.1%, recorded for more than 10 μm long PSiNWs. Models based on cone shape of nanowires located in a circular and rectangular bases were used to calculate the reflectance employing the Transfert Matrix Formalism (TMF) of the PSiNWs layer. Using TMF, the Bruggeman model was used to calculate the refractive index of PSiNWs layer. The calculated reflectance using circular cone shape fits better the measured reflectance for PSiNWs. The remarkable decrease in optical reflectivity indicates that PSiNWs is a good antireflective layer and have a great potential to be utilized in radial or coaxial p-n heterojunction solar cells that could provide orthogonal photon absorption and enhanced carrier collection.

https://hal.archives-ouvertes.fr/hal-00724474/document

Ultra-low reflection porous silicon nanowires for solar cell applications

The present disclosure provides a thermoelectric power management system that includes an electronic device comprising a user interface and a thermoelectric device. The thermoelectric device comprises a thermoelectric unit, a coupler, at least one fastener coupled to the thermoelectric unit and a separate heat expelling unit in thermal communication with the thermoelectric unit. The thermoelectric unit comprises a heat transfer surface that rests adjacent to a body surface of a user and the coupler removably secures the electronic device against the thermoelectric unit. Moreover, the at least one fastener secures the thermoelectric device to the body surface of the user and the thermoelectric device, during use, generates power upon flow of thermal energy from the heat transfer surface to the separate heat expelling unit.

Thermoelectric devices and systems

A technique relates to a qubit readout system. A cavity-qubit system has a qubit and a readout resonator and outputs a readout signal. A lossless superconducting circulator is configured to receive the microwave readout signal from the cavity-qubit system and transmit the microwave readout signal according to a rotation. A quantum limited directional amplifier amplifies the readout signal. A directional coupler is connected to and biases the amplifier to set a working point. A microwave bandpass filter transmits in a microwave frequency band by passing the readout signal while blocking electromagnetic radiation outside of the microwave frequency band. A low-loss infrared filter has a distributed Bragg reflector integrated into a transmission line. The low-loss filter is configured to block infrared electromagnetic radiation while passing the microwave readout signal. The low-loss infrared filter is connected to the microwave bandpass filter to receive input of the microwave readout signal.

High fidelity and high efficiency qubit readout scheme

An optical construction includes a quantum dot film element including a plurality of quantum dots, a first optical recycling element, and a first low refractive index element separating the quantum dot film element from the first optical recycling element. The first low refractive index element has a refractive index of 1.3 or less.

Integrated quantum dot optical constructions

A vapor phase method for forming a thermoelectric element comprises providing a substrate in a reaction space, the substrate including a pattern of a metallic material adjacent to the substrate, which metallic material is configured to catalyze the oxidation of the substrate. The metallic material is then exposed to a gas having an oxidizing agent and a chemical etchant to form holes in or wires from the substrate.

Systems and methods for forming thermoelectric devices

Traditional solar control applications rely on thin metal films to reflect EM radiation with wavelengths longer than that of the visible spectrum. Unfortunately such films also block radiation in cellular, GPS, and radio frequency bands. In one aspect, the disclosure provides a selectively-blocking filter that uses one or more optical filters tuned to a specific range(s) of wavelengths (e.g. for blocking IR radiation), while readily transmitting other wavelengths (e.g. both visible light and cellular/GPS signals). The filters can be manufactured on both flexible and rigid substrates.

Broadband solar control film

A process for altering the thermoelectric properties of an electrically conductive material is provided. The process includes providing an electrically conducting material and a substrate. The electrically conducting material is brought into contact with the substrate. A thermal gradient can be applied to the electrically conducting material and a voltage applied to the substrate. In this manner, the electrical conductivity, the thermoelectric power and/or the thermal conductivity of the electrically conductive material can be altered and the figure of merit increased.

Process for altering thermoelectric properties of a material

The disclosure provides materials, apparatuses, and methods for making multilayer coatings with a high degree of efficiency and control. In some aspects, for example, coatings are described having multiple layers of nanoparticles and a polyelectrolyte, wherein the nanoparticles form tightly packed monolayers. The interface between monolayers may include polyelectrolyte material. One or more aspects of such monolayers and interfaces are controllable.

Methods, materials and apparatus for improving control and efficiency of layer-by-layer processes

The disclosure provides methods and materials for preparing bridging films. In one aspect, the bridging films are non-porous and are suitable for protecting adjacent porous films. For example, the bridging films contact a porous film and protect the porous film from transfer of gases and/or liquids into the pores of the porous film. In another example, bridging films protect the porous film from abrasion.

Bridging Films for Porous Thin Films

Durable coatings and methods for producing the same are provided, where the coatings may include porous coatings encapsulated with a hardening solution that permeates into the porous structure of the film prior to curing. Curing of the hardening solution within the film provides for a durable coating having sufficient durability for use in many different applications, such as optical applications. Any convenient porous coatings may be used in the subject methods. Also provided are methods for forming a coating formulation, where the formulation includes porous coating particles dispersed in a carrier and the porous coating particles may be optionally encapsulated with a hardening solution prior to dispersion.

Melissa Fardy

Papers

Broadband solar control film

Process for altering thermoelectric properties of a material

Methods, materials and apparatus for improving control and efficiency of layer-by-layer processes

Bridging Films for Porous Thin Films

Methods for encapsulating Layer by Layer films and for preparing specialized optical films