Title

Silicon Carbide White Light Leds For Solid-State Lighting

Keywords

Chromium; Electroluminescence (EL); Laser doping; Selenium; Silicon carbide; White light LEDs

Abstract

White light emitting diodes (LEDs) have been successfully fabricated for the first time in silicon carbide substrates (4H-SiC) using a novel laser doping technique. The donor-acceptor pair (DAP) recombination mechanism for luminescence has been used to tailor these LEDs. Chromium (Cr), which produces multiple acceptor sites per atom, and selenium which produces multiple donor sites per atom were successfully incorporated into SiC for the first time using laser doping. Aluminum (Al) and nitrogen (N) were also laser-doped into SiC. Green (521-575 nm) and blue (460-498 nm) wavelengths were observed due to radiative recombination transitions between donor-acceptors pairs of N-Cr and N-Al respectively, while a prominent violet (408 nm) wavelength was observed due to transitions from the nitrogen level to the valence band level. The red (698-738 nm) luminescence was mainly due to nitrogen excitons and other defect levels. This RGB combination produced a broadband white light spectrum extending from 380 to 900 nm. The color space tri-stimulus values were X = 0.3322, Y = 0.3320 and Z = 0.3358 as per 1931 CIE (International Commission on Illumination) for 4H-SiC corresponding to a color rendering index of 96.56; the color temperature of 5510 K is very close to average daylight (5500 K).

Publication Date

1-1-2007

Publication Title

Proceedings of SPIE - The International Society for Optical Engineering

Volume

6486

Number of Pages

-

Document Type

Article; Proceedings Paper

Personal Identifier

scopus

DOI Link

https://doi.org/10.1117/12.724918

Socpus ID

34248672842 (Scopus)

Source API URL

https://api.elsevier.com/content/abstract/scopus_id/34248672842

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