Light emitting diode

US4184170A · kind A · utility

Assignee

• Xerox Corporation · US

Inventors

• Robert D. Burnham · Wheaton, US
• Donald R. Scifres · San Jose, US
• Eric G. Rawson · Saratoga, US

Key dates

• Filing date: Aug 25, 1978
• Grant date: Jan 15, 1980
• Expiry date: Aug 25, 1998

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10H20/824

Abstract

An LED in which the recombination region is comprised of a first layer which is degenerately doped (.apprxeq.10.sup.19 /cm.sup.3) and a second layer which is less degenerately doped (.apprxeq.3.times.10.sup.18 /cm.sup.3). The reduced doping of the second layer provides a depletion region which is wider than the depletion region of conventional LED's whereby carrier tunneling (and non-radiative recombination from such tunneling) is reduced. The second layer is only as thick as necessary (.apprxeq.150A) to reduce tunneling (excess current) significantly which permits substantial radiation by improved carrier injection into the first (heavily doped) portion. The heavy doping of the first layer allows the LED to respond very quickly to switching signals whereby improved light output is achieved with a great reduction in non-radiative recombination due to tunneling.