Abstract:
A method for forming a photovoltaic cell which includes forming a nanostructured layer in a semiconductor material having a plurality of pores opening onto a surface, the plurality of pores having a depth greater than about 1 micron and a diameter between about 5 nanometers and about 1,200 nanometers, and disposing an organic charge-transfer material in the pores of the nanostructured layer. A first electrode is attached to the semiconductor material, and a second electrode is attached to the organic charge-transfer material. The semiconductor material has a thickness between about 5 microns and about 700 microns. Desirably, the nanostructured layer has a porosity of less than the porosity corresponding to the percolation threshold, and the organic charge-transfer material extends at least about 100 nm from the surface of the nanostructured layer. The organic charge-transfer material may partially cover the sides of the pores of the nanostructured layer thereby providing a generally cylindrical cavity therein.
Abstract:
A silicon-on-insulator (SOI) substrate is anodically bonded to a glass substrate in a MEMS structure with or without electrically bypassing the insulator layer by electrically comprising the silicon layers. The insulator layer serves as an etch stop to create a well-defined, thin silicon membrane for a sensor. A second glass substrate is anodically bonded to the other side of the SOI substrate, and debonding of the existing anodic bond prevented by eliminating any potential drop across the existing bonded surface.
Abstract:
An improved optical pressure sensor determines the pressure of the fluid to be monitored by the deflection of a diaphragm in the pressure chamber of the sensor which has an inlet from the measured vessel. The deflection of the diaphragm is determined by monitoring the interference of diode light reflected from the diaphragm and a silicon grating structure superimposed over the diaphragm, at critical positions. Intensity detectors are placed at critical positions such as the specific orders of the diffraction grating to measure the interference intensity of the reflected light. The interferometric accuracy with which the pressure measurement is made with the present invention far exceeds that obtained with optical pressure sensors described in the prior art.
Abstract:
An improved tunable diode laser is capable of fast digital line selection over a broad wavelength spectrum, and uses no moving parts. A focusing element, such as a mirror or a lens, used in combination with a micromirror array serves as the retroreflector in a typical Littman-Metcalf laser cavity. This configuration provides arbitrary, simultaneous, and/or sequential line selection capability over a very broad wavelength range. The use of an individually-controllable micromirror array eliminates the high precision mechanical motion of a grating element and improves the overall durability and ruggedness of the device. The present invention can be integrated into any diode laser and has significant application in spectroscopy.