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. 11, 2000
Filed:
Feb. 10, 1997
Harry R Clark, Jr, Townsend, MA (US);
Massachusetts Institute of Technology, Cambridge, MA (US);
Abstract
An electroluminescent display device having a semiconductor host matrix which is characterized by a conduction band energy level, a valence band energy level, and a bandgap energy corresponding to an energy difference between a minima of the conduction band and a maxima of the valence band energy levels. Semiconductor particles are disposed in the semiconductor host matrix, and at least a portion of these semiconductor particles are characterized by a conduction band energy level that is less than that of the host matrix. These semiconductor particles are further characterized by a valence band energy level and a bandgap energy, corresponding to an energy difference between a minima of the conduction band and a maxima of the valence band energy levels of the particles, that is less than the bandgap energy of the semiconductor host matrix. There is included in the display configuration a mechanism for providing electrons and holes at locations of the semiconductor particles, by way of conduction through the semiconductor host matrix, for recombination at the particle locations, between the conduction band minima and the valence band maxima of the particles, to produce luminescent radiation. With a semiconductor host matrix that enables conduction of holes and electrons freely through it, the electroluminescent display of the invention overcomes the severe quantum efficiency limitations imposed by conventional luminescent display configurations.