Browse Prior Art Database

Field Effect Integrated Injection LED Visible or IR Source

IP.com Disclosure Number: IPCOM000052466D
Original Publication Date: 1981-Jun-01
Included in the Prior Art Database: 2005-Feb-11
Document File: 3 page(s) / 74K

Publishing Venue

IBM

Related People

Fang, FF: AUTHOR [+2]

Abstract

An LED (light-emitting diode) and an FET (field-effect transistor) like control transistor may be integrated to form a simple light-emitting structure, which can be arrayed in two dimensions for display or printing applications.

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Field Effect Integrated Injection LED Visible or IR Source

An LED (light-emitting diode) and an FET (field-effect transistor) like control transistor may be integrated to form a simple light-emitting structure, which can be arrayed in two dimensions for display or printing applications.

Matrix addressing of two-dimensional arrays of LEDs is usually accomplished by using remote switching elements, such as transistors. The arrays are often divided into isolated rows or columns of small bars, each with diodes having a common cathode.

We propose to integrate the control devices intimately with the LEDs, one control device per LED, using the simple structure shown in Fig. 1. Substrate 10 is p-type material upon which is grown an n-type epitaxial layer 12. This layer 12 may be either homo- or hetero-epitaxy, e.g., GaAs on GaAs, GaA1As on GaAs, GaAsP on GaAs, or any other III-V ternary or quaternary compound semiconductors. Structures such as GaP on Si might be used as well. Two p-type areas 14, 16 are formed (e.g.. by diffusion or ion implantation), as shown.

The central closed region 14 is separated by a small space 18 from the annular ring 16. This ring 16 is reverse-biased to control injection current flowing from the center (LED) region 14, which is positively biased to surrounding ohmic electrode 20 formed on the n-type layer 12 and grounded.

In operation, a suitably forward biased voltage applied to the central region 14 will cause light to be emitted from that region unless the current is "cut off" by a suitable negative bias applied to the ring 16. The degree of bias determines the amount of light. The p-type substrate may also be bi...