Radiation assisted electrostatic separation of semiconductor materials
AssigneeEmpire Technology Development LLC
InventorThomas A. Yager
Life of this patent
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Abstract
A method of separating material includes providing a mixture of a first material, such as a semiconductor, and a second material, such as an insulator or a different semiconductor. The mixture can be irradiated using a light source at a wavelength that causes the first material's conductivity to increase while leaving the second material's conductivity (substantially) unchanged. Placing the mixture in contact with a ground electrode discharges the first material but not the second material due the difference in their conductivities. Applying an electric field to the discharged mixture separates the discharged first material from the second material.
Claims25
A method of separating material, the method comprising:
- irradiating a mixture of a first material and a second material at a wavelength that induces a difference in conductance between the first material and the second material;
- and
- applying an electric field to the mixture, the electric field causing at least some of the first material to separate from the second material due to the difference in conductance,
- wherein the wavelength corresponds to an energy that is (a) greater than a band gap energy of the first material, and (b) less than a band gap energy of the second material.
(canceled)
An apparatus for separating material, the apparatus comprising:
- a source configured to irradiate a mixture of a first material and a second material at a wavelength that induces a difference in conductance between the first material and the second material;
- and
- a pair of electrodes configured to apply an electric field to the mixture that causes separation of at least some of the first material from the second material based on the difference in conductance,
- wherein the wavelength corresponds to an energy that is (a) greater than a band gap energy of the first material, and (b) less than a band gap energy of the second material.
(canceled)
Dependencies are inferred from the claim text.