Phosphor-free InGaN/AlGaN core-shell nanowire light-emitting diodes (LEDs) grown by molecular beam epitaxy have been developed and their application in visible light communication (VLC) has been investigated. The electroluminescence spectra of these nanowire LEDs show a very broad spectral linewidth and fully covers the entire visible spectrum. High-brightness phosphor-free LEDs with highly stable white-light emission and high color-rendering index (CRI) of >98 were obtained by controlling the Indium composition in the device active region. Moreover, the phosphor-free nanowire white-LEDs exhibit relatively high 3-dB frequency bandwidth of ~ 1.4 MHz which is higher compared to that of phosphor-based white LEDs at the same measurement condition. Such high-performance phosphorfree nanowire LEDs are being further improved and are ideally suited for future smart lighting applications and communications.
We report on the achievement of relatively high power phosphor-free white light-emitting diodes (LEDs) using a new self-organized InGaN/AlGaN dot-in-a-wire core-shell nanowire heterostructure. Multiple AlGaN shell layers are spontaneously formed during the growth of the quantum dot active region. Due to the drastically reduced nonradiative surface recombination, such core-shell nanowire structures exhibit significantly increased carrier lifetime (from ~ 0.3ns to ~ 4.5ns) and massively enhanced photoluminescence intensity. Strong white-light emission was recorded for the unpackaged core-shell nanowire LEDs with an output power of >5 mW, measured under an injection current ~ 60A/cm2, with a color rendering index of ~ 95.
One of the grand challenges for future solid state lighting is the development of high efficiency, phosphor-free white light emitting diodes (LEDs). In this context, we have investigated the molecular beam epitaxial growth and characterization of nanowire LEDs on Si, wherein intrinsic white-light emission is achieved by incorporating selforganized InGaN quantum dots in defect-free GaN nanowires on a single chip. We have further demonstrated that, with the incorporation of p-type modulation doping and AlGaN electron blocking layer, InGaN/GaN dot-in-a-wire white LEDs can exhibit nearly zero efficiency droop and significantly enhanced internal quantum efficiency (up to ~57%) at room-temperature.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.