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:
Sep. 03, 1985
Filed:
Jun. 28, 1984
Torgny Brogardh, Vaster.ang.s, SE;
Christer Ovren, Vaster.ang.s, SE;
Asea Aktiebolag, Vaster.ang.s, SE;
Abstract
A sensor element adaptable for measurement of a physical parameter formed of a crystalline material and emitting luminescent spectra upon excitation by light spectra and the influence of said physical parameter. A first layer emitting luminescent spectra is formed of a semiconductor material containing dopant providing shallow energy levels and recombination centers with a concentration between 10.sup.15 to 10.sup.18 cm.sup.-3, and sandwiched between second and third layers of semiconductor material having low absorption for light excitation of the first layer, and the respective lattice constants of the second and third layers being substantially coincidental with the lattice constant of the first layer. The sensor element is formed of GaAs for the substrate and AlGaAs for the semiconductor layers, with appropriate variation in the concentration Al, Ga, and As for the various layers. Generally, the energy band gap of the layers sandwiching the luminescent emitting layer are higher than that of the emitting layer. In a modified embodiment, GaAs is used as the luminescence emitting layer with covering semiconductor layers of AlGaAs, with appropriate variation in the concentration of Al, Ga and As. In a further modification an additional semiconductor layer of AlGaAs is sandwiched between the active semiconductor layer and a non-active semiconductor layer to reduce or eliminate a shift in the wavelength emission of the sensor element.