Violet-emitting diode may operate at room temperature

Dec. 1, 1995

Fabrication of a violet-emitting diode laser from gallium nitride (GaN) based wide-bandgap materials will be described by researchers from the Nagoya Institute of Technology (Nagoya, Japan) at the 41st annual IEEE International Electron Devices Meeting (Dec. 10-13, 1995, Washington, DC). The researchers' paper is the first to report pulsed stimulated emission at 300 K from a current-injected surface-emitting InGaN/AlGaN double-heterostructure diode whose active layer comprises InGaN co-doped with silicon and zinc.

At injection currents above 400 mA, the main emission wavelength is 380 nm, which originates from band-to-band emission in the InGaN layer. A weaker emission at 440 nm is attributed by the researchers to impurity in the same layer and saturates as the injected current increases above 800 mA.

Although stimulated emission from photopumped GaN devices has been reported at temperatures up to 425 K, only spontaneous emission has previously been observed at 300 K with current injection. The researchers hope their technique can be developed for diode-laser operation at room temperature.

About the Author

Stephen G. Anderson

Director, Industry Development - SPIE

Stephen Anderson is a photonics industry expert with an international background and has been actively involved with lasers and photonics for more than 30 years. As Director, Industry Development at SPIE – The international society for optics and photonics – he is responsible for tracking the photonics industry markets and technology to help define long-term strategy, while also facilitating development of SPIE’s industry activities. Before joining SPIE, Anderson was Associate Publisher and Editor in Chief of Laser Focus World and chaired the Lasers & Photonics Marketplace Seminar. Anderson also co-founded the BioOptics World brand. Anderson holds a chemistry degree from the University of York and an Executive MBA from Golden Gate University.