NEGATIVE RESISTANCE LIGHT EMITTING DIODE DEVICE

• US 3,701,043 A
• Filed: 02/16/1970
• Issued: 10/24/1972
• Est. Priority Date: 02/16/1970
• Status: Expired due to Term

• Current Assignee: Rainer Zuleeg, Uri Ranon
• Original Assignee: Rainer Zuleeg, Uri Ranon
• Inventors: Zuleeg, Rainer, Ranon, Uri
• Primary Examiner(s): Wibert, Ronald L.
• Assistant Examiner(s): Webster, R. J.
• Application Number:
  US05/011,410
• Time in Patent Office: 981 Days
• Field of Search: 331/94.5 317/234.10 307/17G
• US Class Current: 372/50.1
• CPC Class Codes: H01L 33/00 Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof H10K50/00 takes precedence; devices consisting of a plurality of semiconductor components formed in or on a common substrate and including semiconductor components having potential barriers, specially adapted for light emission H01L27/15; semiconductor lasers H01S5/00
• CPC Class Codes: H01S 5/042 Electrical excitation ; Circuits therefor monolithically integrated laser drive components H01S5/0261
• CPC Class Codes: H01S 5/0422 with n- and p-contacts on the same side of the active layer

Abstract

Diode device comprising a light emitting diode fabricated of a semiconductor having bulk negative resistance properties. The diode includes a light emitting P N junction and a N-type layer or section of predetermined resistivity and geometry. The diode device has a voltage-current characteristic including two current-controlled, negative resistance portions separated by a region wherein the device is unstable and produces free oscillations which are in phase with intensity variations simultaneously produced in the emitted light. Bistable operation of the device can be obtained by suitable placement of its load line through either of the negative resistance portions. A diode device embodiment including a Fabry-Perot cavity structure therein produces a coherent light beam which can be readily modulated at microwave frequencies.

Claims

1. A negative resistance, light emitting diode device system comprising:

a light emitting diode fabricated of a semiconductor having Gunn domain and filament forming bulk negative resistance properties, said diode including first and second sections of respectively different first and second types of electrical conductivity material having a light emitting junction therebetween, and said second section having a predetermined resistivity and geometry for producing said domains and filaments therein;

first and second contact means for providing respective electrical connections to said first and second sections, said first and second contact means being adapted to be connected to a source of voltage, and said diode device has a forward voltage versus current characteristic which includes a region representative of unstable operation wherein oscillating conditions involving said domains and filaments prevail and light emission intensity from said light emitting junction varies in phase with current amplitude through said diode device, said first-type material is P -type material and said secondtype material is N-type material, and said first and second sections are disposed in a generally vertical arrangement whereby a sandwich form of said diode device can be obtained, and including a thin layer of a third-type of material provided generally under said second contact means and constituting an ohmic contact for said second section, and wherein said thirdtype material is N -type material and said light emitting junction is spaced a predetermined distance vertically from said thin layer, said sandwich form of said diode device including a pair of rough vertical parallel surfaces and a pair of smooth vertical parallel surfaces for a Fabry-Perot cavity structure, and including reflector means affixed to one of said smooth surfaces over said light emitting junction portion thereof whereby an intensity-oscillating coherent light beam of a predetermined Gunn domain frequency as established essentially by said semiconductor and said predetermined distance, can be emitted from said light emitting junction portion of the other of said smooth surfaces; and

a high Q tuned circuit means connected to said diode device for producing an intensity-oscillating coherent light beam of a resonant mode frequency of said predetermined Gunn domain frequency from said light emitting junction portion of said other of said smooth surfaces of said diode device, said high Q tuned circuit means comprising a resonator mounting said diode device therein and connected thereto for producing said intensity-oscillating coherent light beam of a resonant mode frequency of said predetermined Gunn domain frequency, and including means connecting with said resonator for modulating said light beam at microwave frequencies, said resonator including adjustable plunger means for tuning it to a selected resonant mOde frequency and adapted to connect said source of voltage to said diode device in said resonator, and window means for transmitting said light beam through a wall of said resonator.

2. A negative resistance, light emitting diode device comprising:

a light emitting diode fabricated of a semiconductor having Gunn domain and filament forming bulk negative resistance properties, said diode including first and second sections of respectively different first and second types of electrical conductivity material having a light emitting junction therebetween, and said second section having a predetermined resistivity and geometry for producing said domains and filaments therein; and

first and second contact means for providing respective electrical connections to said first and second sections, said first and second contact means being adapted to be connected to a source of voltage, and said diode device has a forward voltage versus current characteristic which includes, with increasing current, a first region representative of stable non-oscillatory and low light emission operation, a second region representative of unstable operation wherein oscillating conditions involving said domains and filaments prevail and light emission intensity from said light emitting junction varies in phase with current amplitude through said diode device, and a third region representative of stable non-oscillatory and intense light emission operation, said first and second sections being generally parallel and contiguous rectangular sections of a thin film layer of material and disposed in a generally lateral arrangement whereby a planar form of said diode device is obtained, and including a semi-insulating substrate for supporting said thin film layer with its laterally disposed sections, and wherein said first and second contact means are affixed respectively to the exposed faces of said first and second sections, said first-type material is P -type material and said second-type material is N-type material, and including a thin contact layer of a third-type of material provided generally under said second contact means and constituting an ohmic contact for said second section, and wherein said third-type material is N -type material and said thin contact layer is generally rectangular and disposed in a laterally parallel arrangement with an adjacent side spaced at a predetermined distance from said light emitting junction, and said characteristic includes current-controlled, negative resistance representative portions at transitions of said first to second regions and said second to third regions, respectively, and including a load resistance connected in series with said diode device and said source of voltage, said load resistance being of a predetermined value to establish a load line through said second region whereby relaxation oscillations having a frequency generally proportional inversely to applied voltage are produced by said diode device.

3. The invention as defined in claim 2 wherein said semiconductor is essentially gallium arsenide and said load resistance is of a predetermined value to establish said load line near one of said transition portions whereby a bistable diode device is obtained, and including trigger means connected to apply a signal to said diode device to switch the same from one stable state to another.