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High Efficiency Light Emitting Diodes

IP.com Disclosure Number: IPCOM000080673D
Original Publication Date: 1974-Jan-01
Included in the Prior Art Database: 2005-Feb-27
Document File: 2 page(s) / 39K

Publishing Venue

IBM

Related People

Pogge, HB: AUTHOR

Abstract

It has been found that the need for grading an epitaxial layer to a final composition position in light-emitting diodes, in order to minimize the lattice mismatch, can be eliminated by the use of a composition of GaAs(.41)Sb(.17)P(.42) which allows its direct growth on GaAs substrates, without lattice mismatch and thermal coefficient of expansion mismatch. This minimizes the dislocation density in the epitaxial film and, therefore, will increase the potential light efficiency of the diode. The pertinent data is shown in the accompanying diagrams of Figs. 1 and 2.

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High Efficiency Light Emitting Diodes

It has been found that the need for grading an epitaxial layer to a final composition position in light-emitting diodes, in order to minimize the lattice mismatch, can be eliminated by the use of a composition of GaAs(.41)Sb(.17)P(.42) which allows its direct growth on GaAs substrates, without lattice mismatch and thermal coefficient of expansion mismatch. This minimizes the dislocation density in the epitaxial film and, therefore, will increase the potential light efficiency of the diode. The pertinent data is shown in the accompanying diagrams of Figs. 1 and 2.

As will be appreciated, since the band-gap energy decrease for GaAs(.83)Sb(.17) is 0.12 ev and the increase for GaAs(.68)P(.42)is 0.58 ev, a net increase in band-gap energy is 0.46 ev over-that of GaAs, or 1.88 ev which is red color emission. Thus GaAs(.41)P(.42)Sb(.17) can be grown on GaAs with minimal lattice mismatch and cooled down to room temperature without thermally induced stresses.

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