Phosphor-Free GaN-Based Transverse Junction Light Emitting Diodes for the Generation of White Light

• Published in: IEEE photonics technology letters Vol. 18; no. 24; pp. 2593 - 2595
• Main Authors: Shi, J.-W., Huang, H.-Y., Wang, C.-K., Sheu, J.-K., Lai, W.-C., Wu, Y.-S., Chen, C.-H., Chu, J.-T., Kuo, H.-C., Wei-Ping Lin, Tsung-Hsun Yang, Chyi, J.-I.
• Format: Journal Article
• Language: English
• Published: New York IEEE 15.12.2006; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Bias; Electroluminescence; Flattening; Gallium nitride; GaN light-emitting-diode (LED); Light emitting diodes; Optical pumping; Optical saturation; P-n junctions; Phosphors; Quantum well devices; Spectra; Stimulated emission; Wavelengths; White light; white-light generation; Zinc
• ISSN: 1041-1135; 1941-0174
• DOI: 10.1109/LPT.2006.887362

We demonstrate a GaN-based phosphor-free near-white-light light-emitting-diode (LED) structure that operates in the visible wavelengths and offers broadening and flattening optical bandwidth performance. The incorporation of GaN-based dual wavelengths (blue and green) multiple-quantum-wells with a transverse p-n junction produces a device which can directly generate stable and near visible white-light emissions. The shape of the optical spectra (440-560 nm) are invariable from low to very high levels of bias currents. The problems of nonuniform carrier distribution and bias dependent electroluminescence spectra that occur in traditional phosphor-free white-light or near-white-light LEDs (with vertical p-n junctions) are eliminated by the demonstrated structure