Systems and methods for light absorption and field emission using microstructured silicon
AssigneePresident and Fellows of Harvard College
InventorsEric Mazur, James Edward Carey, III, Catherine H. Crouch, Rebecca Jane Younkin, Claudia Wu
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Abstract
Methods and systems for absorbing infrared light, and for emitting current are described. A sample, such as a sample containing mainly silicon, is microstructured by at least one laser pulse to produce cone-like structures on the exposed surface. Such microstructuring enhances the infrared absorbing, and current emission properties of the sample.
Claims21
A method for detecting infrared radiation, the method comprising the steps of:
- providing a semiconductor having a plurality of microstructures formed thereon by laser light, the semiconductor possessing a band gap energy, Ebg;
- exposing said semiconductor to electromagnetic radiation to allow the sample to absorb a portion thereof, said electromagnetic radiation having a frequency smaller than Ebg divided by Planck's constant;
- harnessing energy from the absorbed radiation in a photodetector by converting said absorbed radiation having said frequency smaller than Ebg divided by Planck's constant into an electrical signal, said signal being indicative of an intensity of said absorbed radiation having a frequency smaller than Ebg divided by Planck's constant;
- and utilizing said signal to indicate an intensity of the absorbed radiation having a frequency smaller than Ebg divided by Planck's constant on a display.
A method for detecting infrared radiation, the method comprising the steps of:
- providing a sample composed of primarily silicon having a plurality of microstructures formed thereon by laser light;
- exposing said sample to electromagnetic radiation to allow the sample to absorb a portion thereof, said electromagnetic radiation having one or more wavelengths greater than about 1.05 micrometers, and
- utilizing said sample in a photodetector to convert the radiation energy at said one or more wavelengths greater than about 1.05 micrometers to at least one electrical signal, said signal being indicative of an intensity of said absorbed radiation having one or more wavelengths greater than about 1.05 micrometers, and
- utilizing said signal to indicate an intensity of the absorbed radiation having one or more wavelengths greater than about 1.05 on a display.
A method for photodetection of infrared radiation, comprising
- irradiating a silicon substrate surface with a plurality of short laser pulses while exposing said surface to a background gas selected from the group consisting of a halogenic gas, nitrogen and air,
- exposing said laser-treated surface in a photodetector to radiation having one or more wavelengths greater than about 1.05 microns to convert the radiation at said one or more wavelengths greater than about 1.05 microns to one or more electrical signals, and
- utilizing said signals to indicate intensities of the absorbed radiation having one or more wavelengths greater than about 1.05 on a display.
Dependencies are inferred from the claim text.