An article by an NJIT graduate student that describes a novel approach to engineering highly efficient LED lighting, covering the entire range of the visible spectrum, is featured this month as the ‘Editor’s Pick’ in the peer-reviewed Journal of Vacuum Science and Technology B.
Written by Moab Rajan Philip, a second-year Ph.D. student in the Department of Electrical and Computer Engineering, the paper, “Controlling Color Emission of InGaN/AlGaN Nanowire Light-Emitting Diodes Grown by Molecular Beam Epitaxy,” is based on ongoing research in NJIT’s Nano-Optoelectronic Materials and Devices Laboratory.
The laboratory, directed by Hieu P. Nguyen, an assistant professor of electrical and computer engineering, develops high-performance nanophotonic and nanoelectronic devices for lighting and energy-storage applications. These devices are fabricated from gallium nitride (III-nitride)-based semiconductors in the form of nanostructures devised through a state-of-the-art epitaxial growth technique, called molecular beam epitaxy (MBE) – a method for depositing crystals on a substrate.
In their published research, the group reported full-color emission from LEDs that covers nearly the entire visible wavelength range by engineering structures grown by MBE.
“The current white-LED lighting technology is not efficient. To generate white light, current LED lamps rely on the use of phosphors to convert blue light into green and red light, while this limits the device’s efficiency, increases the manufacturing cost and compromises reliability,” Nguyen says. “The goal of our research on nanowire white LEDs is to improve on this process by eliminating the phosphor coating and by integrating LEDs on low-cost, large-area substrates. We believe this method is especially useful in dissipating heat.”
“When used in applications such as lasers, the technology must also be absolutely precise,” adds Philip, who plans to work in research and development after he graduates to invent solid-state lighting devices that are “innovative and useful.”
Nguyen’s research group includes Philip, Dipayan Datta Choudhary, Mehrdad Djavid and Nasiruddin Bhuyian.