Nitride-based cascade near white light-emitting diodes

Author

Chen, C.H. ; Chang, S.J. ; Su, Y.K. ; Sheu, J.K. ; Chen, J.F. ; Kuo, C.H. ; Lin, Y.C.

Author_Institution

Dept. of Electr. Eng., Nat. Cheng Kung Univ., Tainan, Taiwan

Volume

14

Issue

7

fYear

2002

fDate

7/1/2002 12:00:00 AM

Firstpage

908

Lastpage

910

Abstract

An InGaN-GaN blue light-emitting diode (LED) structure and an InGaN-GaN green LED structure were grown sequentially onto the same sapphire substrate so as to achieve a nitride-based near white LED. In order to avoid thyristor effect, we choose a large 2.1/spl times/2.1 mm/sup 2/ LED chip size, which was six times larger than that of the normal LED. It was found that we could observe a near white light emission with Commission International de l´Eclairage color coordinates x=0.2 and y=0.3, when the injection current was lower than 200 mA. It was also found that the output power, luminous efficiency and color temperature of such a cascade near white LED were 4.2 mW, 81 l m/W, and 9000 K, respectively.

Keywords

MOCVD; brightness; colour; gallium compounds; indium compounds; laser beams; light emitting diodes; quantum well devices; semiconductor heterojunctions; vapour phase epitaxial growth; 200 mA; 4.2 mW; 9000 K; Commission International de l´Eclairage color coordinates; InGaN-GaN; LED; LED chip size; blue light-emitting diode; cascade near white LED; color temperature; injection current; light-emitting diode green; luminous efficiency; near white light emission; nitride-based cascade near white light-emitting diodes; nitride-based near white LED; output power; sapphire substrate; Epitaxial growth; Gallium nitride; Light emitting diodes; Liquid crystal displays; Microelectronics; Phosphors; Photonics; Power generation; Quantum well devices; Recycling;

fLanguage

English

Journal_Title

Photonics Technology Letters, IEEE

Publisher

ieee

ISSN

1041-1135

Type

jour

DOI

10.1109/LPT.2002.1012381

Filename

1012381