Dismiss
InnovationQ will be updated on Sunday, Oct. 22, from 10am ET - noon. You may experience brief service interruptions during that time.
Browse Prior Art Database

Ternary Logic Device

IP.com Disclosure Number: IPCOM000094690D
Original Publication Date: 1965-Apr-01
Included in the Prior Art Database: 2005-Mar-06
Document File: 2 page(s) / 37K

Publishing Venue

IBM

Related People

Pilkuhn, MH: AUTHOR [+2]

Abstract

GaP or GaAs(x)P(1-x) light emitting diodes can be made which emit light at two different peak wavelengths depending upon the bias applied. Characteristic values for GaP are, for instance, 6150 angstroms peak emission for forward bias depending on impurity type and 7900 angstroms peak emission for reverse bias at room temperature.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 73% of the total text.

Page 1 of 2

Ternary Logic Device

GaP or GaAs(x)P(1-x) light emitting diodes can be made which emit light at two different peak wavelengths depending upon the bias applied. Characteristic values for GaP are, for instance, 6150 angstroms peak emission for forward bias depending on impurity type and 7900 angstroms peak emission for reverse bias at room temperature.

This effect is used to build a ternary logic device by employing two different photosensitive detectors, one of each tuned to one of the two emission peaks. In this way, it is possible to distinguish optically. between the applied bias of the active element. One arrangement is depicted in the upper drawing. In the case of forward biasing the light emitting junction (red peak emission), only detector 2 receives a signal. In the case of reverse bias (yellow peak emission), both devices respond to the signal if the yellow component is not filtered out before it reaches detector 2.

An integrated structure is made as shown in the lower drawing. Starting with a diffused PN junction in GaP, N-type GaAs is vapor grown on part of the N-side of GaP. The thickness of the N-type GaAs can be chosen in such a way that it acts as a filter. PN junctions are then formed in the N-type GaAs and the adjacent N-type GaP. The same structure can be obtained by starting with a GaAs(x)P(1x) alloy if x is smaller than 0.5. In the case of a reversed biased diode, both detectors respond to the signal. A filter which blocks yellow light is place...