Expand this Topic clickable element to expand a topic
Skip to content
Optica Publishing Group

Metal-nitride-oxide-semiconductor light-emitting devices for general lighting

Open Access Open Access

Abstract

The potential for application of silicon nitride-based light sources to general lighting is reported. The mechanism of current injection and transport in silicon nitride layers and silicon oxide tunnel layers is determined by electro-optical characterization of both bi- and tri-layers. It is shown that red luminescence is due to bipolar injection by direct tunneling, whereas Poole-Frenkel ionization is responsible for blue-green emission. The emission appears warm white to the eye, and the technology has potential for large-area lighting devices. A photometric study, including color rendering, color quality and luminous efficacy of radiation, measured under various AC excitation conditions, is given for a spectrum deemed promising for lighting. A correlated color temperature of 4800K was obtained using a 35% duty cycle of the AC excitation signal. Under these conditions, values for general color rendering index of 93 and luminous efficacy of radiation of 112 lm/W are demonstrated. This proof of concept demonstrates that mature silicon technology, which is extendable to low-cost, large-area lamps, can be used for general lighting purposes. Once the external quantum efficiency is improved to exceed 10%, this technique could be competitive with other energy-efficient solid-state lighting options.

©2011 Optical Society of America

Full Article  |  PDF Article
More Like This
Optimal spectra of white light-emitting diodes using quantum dot nanophosphors

Ping Zhong, Guoxing He, and Minhao Zhang
Opt. Express 20(8) 9122-9134 (2012)

Improved color rendering and luminous efficacy in phosphor-converted white light-emitting diodes by use of dual-blue emitting active regions

Roya Mirhosseini, Martin F. Schubert, Sameer Chhajed, Jaehee Cho, Jong Kyu Kim, and E. Fred Schubert
Opt. Express 17(13) 10806-10813 (2009)

Cited By

Optica participates in Crossref's Cited-By Linking service. Citing articles from Optica Publishing Group journals and other participating publishers are listed here.

Alert me when this article is cited.


Figures (6)

Fig. 1
Fig. 1 (a) Cross-sectional view of the two Silicon Nitride MNOSLED structures under study. A1: Tunnel oxide (SiO2) + Si3N4 and A2: Tunnel oxide (SiO2) + Si3N4 + control oxide (SiO2). (b) Top view of a typical device. The semi-transparent gate electrode is the central rectangle with dimensions 10µm x 500 µm.
Fig. 2
Fig. 2 SRIM simulation profile for each structure.
Fig. 3
Fig. 3 (a) Current density (J) vs. gate voltage (V) plot for the MNOSLED. The inset shows the band diagram for struture A1 (b) Poole-Frenkel representation at low voltages. (c) Space charge-limited current representation at high voltages. (d) EL spectra at maximum voltage for both devices. The inset shows the EL emission of A1. This photograph was taken with a standard digital commercial camera. The white square on the right side represents the color extracted directly from the spectrum, which may be interpreted as a true-white correction.
Fig. 4
Fig. 4 Color shifts in the CIE 1931 diagram produced under a change in (a) excitation voltage (T = 10µs and DC = 50%), (b) period of the excitation signal (V = −25V and DC = 50%) and (c) duty cycle of the excitation signal (V = −25V and T = 10µs).
Fig. 5
Fig. 5 Dependence of Correlated Color Temperature (CCT), deviation from the blackbody locus (DUV), Luminous Efficacy of Radiation (LER) and Color Rendering Index (CRI) on Voltage (a) and on Duty Cycle (b).
Fig. 6
Fig. 6 (a) Musell region in the CIE 1931 diagram. (b) Color Rendering Map (CRM) of the spectrum excited through a waveform of −25V amplitude, 10µs period and 35% duty cycle.

Equations (2)

Equations on this page are rendered with MathJax. Learn more.

J E exp [ ( 1 / k B T ) e 3 E / π ε 0 ε r ] ,
J = 9 ε 0 ε r µ E 2 / 8 d ,
Select as filters


Select Topics Cancel
© Copyright 2024 | Optica Publishing Group. All Rights Reserved