The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 07, 1987
Filed:
Sep. 20, 1984
George F Garlick, Los Angeles, CA (US);
Hughes Aircraft Company, Los Angeles, CA (US);
Abstract
The quality of photovoltaic semiconductor material for use in solar cells may be determined through the determination of the minority carrier diffusion length, in a simple manner. First, a thick slug or a thin plate or slice of the semiconductor material is polished on the front side, and mechanically finished in a predetermined manner on the back side. Then light at two different wavelengths, is applied to the plate, and the photovoltage and light intensity is measured first with light of one wavelength incident thereon, and then with light of the other wavelength. The ratio of the two intensities required to give the same output photovoltage determines the minority carrier diffusion length. The apparatus includes a light chopper, a photocell or thermocouple for determining relative intensity, and a simple mounting cell, for non-destructively coupling to the semiconductor sample with sensing electrodes, on the opposite sides of the sample. The circuitry may include a digital voltmeter and a microprocessor.