Browse Prior Art Database

GaAlAs Negative Resistance Light Emitting Diode

IP.com Disclosure Number: IPCOM000079511D
Original Publication Date: 1973-Jul-01
Included in the Prior Art Database: 2005-Feb-26
Document File: 2 page(s) / 26K

Publishing Venue

IBM

Related People

Boburka, JM: AUTHOR [+2]

Abstract

Multilayer PIN GaAlAs light-emitting diode (LED) 1 is grown by liquid phase epitaxy in a horizontal growth furnace, not shown. Region 2 is a semiinsulating layer, in which the difference in the donor and acceptor impurities (Nd-Na) are very small or approach zero. Under low-forward bias current applied to terminals 3, region 2 restricts current flow through diode 1 by providing a space charge region within the layer 2. Beyond a certain threshold voltage, double injection into region 2 causes diode 1 to exhibit current controlled negative resistance (CCNR) as the region 2 becomes conductivity modulated. That is to say, the resistance of the layer 2 is essentially controlled by the magnitude of the current passing through it.

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 86% of the total text.

Page 1 of 2

GaAlAs Negative Resistance Light Emitting Diode

Multilayer PIN GaAlAs light-emitting diode (LED) 1 is grown by liquid phase epitaxy in a horizontal growth furnace, not shown. Region 2 is a semiinsulating layer, in which the difference in the donor and acceptor impurities (Nd-Na) are very small or approach zero. Under low-forward bias current applied to terminals 3, region 2 restricts current flow through diode 1 by providing a space charge region within the layer 2. Beyond a certain threshold voltage, double injection into region 2 causes diode 1 to exhibit current controlled negative resistance (CCNR) as the region 2 becomes conductivity modulated. That is to say, the resistance of the layer 2 is essentially controlled by the magnitude of the current passing through it.

Beyond a certain threshold voltage double injection increases the life time of carriers in the I region 2 and this causes an increase in the conductivity of region
2. This CCNR is shown in the LED current versus voltage characteristic of Fig.
2. The device 1 exhibits efficient injection luminescence when forward biased beyond the threshold voltage. The LED has a resultant bistable current versus voltage characteristic, cf. Fig. 2, which is particularly useful when the LED is employed as a visual memory element.

The PIN structure of LED 1 reduces the normally high-internal capacitance associated with conventional PN type LED's that are used as photodiodes. In addition, various practical applicatio...