Investigation of the efficiency-droop mechanism in vertical red light-emitting diodes using a dynamic measurement technique

J. W. Shi, F. M. Kuo, Che Wei Lin, Wei Chen, L. J. Yan, Jinn-Kong Sheu

Research output: Contribution to journalArticle

8 Citations (Scopus)

Abstract

The mechanism responsible for the efficiency droop in AlGaInP-based vertically structured red light-emitting diodes (LEDs) is investigated using dynamic measurement techniques. Short electrical pulses (∼100 ps) are pumped into this device and the output optical pulses probed using high-speed photoreceiver circuits. From this, the internal carrier dynamic inside the device can be investigated by use of the measured electrical-to-optical (E-O) impulse responses. Results show that the E-O responses measured under different bias currents are all invariant from room temperature to ∼100 °C. This is contrary to most results reported for AlGaInP-based red LEDs, which usually exhibit a shortening in the response time and degradation in output power with the increase of ambient temperature. According to the extracted fall-time constants of the E-O impulse responses, the origin of the efficiency droop in our vertical LED structure, which has good heat-sinking, is not due to thermally induced carrier leakage, but rather should be attributed to defect recombination and the saturation of defect/spontaneous recombination processes under low and high bias current, respectively.

Original languageEnglish
Article number5983398
Pages (from-to)1585-1587
Number of pages3
JournalIEEE Photonics Technology Letters
Volume23
Issue number21
DOIs
Publication statusPublished - 2011 Oct 21

Fingerprint

Light emitting diodes
light emitting diodes
Bias currents
Impulse response
impulses
Defects
sinking
output
Laser pulses
defects
pulses
time constant
ambient temperature
Degradation
Temperature
leakage
Networks (circuits)
high speed
degradation
saturation

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Atomic and Molecular Physics, and Optics
  • Electrical and Electronic Engineering

Cite this

@article{942240efedd8494f965ea1f2827ff2c2,
title = "Investigation of the efficiency-droop mechanism in vertical red light-emitting diodes using a dynamic measurement technique",
abstract = "The mechanism responsible for the efficiency droop in AlGaInP-based vertically structured red light-emitting diodes (LEDs) is investigated using dynamic measurement techniques. Short electrical pulses (∼100 ps) are pumped into this device and the output optical pulses probed using high-speed photoreceiver circuits. From this, the internal carrier dynamic inside the device can be investigated by use of the measured electrical-to-optical (E-O) impulse responses. Results show that the E-O responses measured under different bias currents are all invariant from room temperature to ∼100 °C. This is contrary to most results reported for AlGaInP-based red LEDs, which usually exhibit a shortening in the response time and degradation in output power with the increase of ambient temperature. According to the extracted fall-time constants of the E-O impulse responses, the origin of the efficiency droop in our vertical LED structure, which has good heat-sinking, is not due to thermally induced carrier leakage, but rather should be attributed to defect recombination and the saturation of defect/spontaneous recombination processes under low and high bias current, respectively.",
author = "Shi, {J. W.} and Kuo, {F. M.} and Lin, {Che Wei} and Wei Chen and Yan, {L. J.} and Jinn-Kong Sheu",
year = "2011",
month = "10",
day = "21",
doi = "10.1109/LPT.2011.2164574",
language = "English",
volume = "23",
pages = "1585--1587",
journal = "IEEE Photonics Technology Letters",
issn = "1041-1135",
publisher = "Institute of Electrical and Electronics Engineers Inc.",
number = "21",

}

Investigation of the efficiency-droop mechanism in vertical red light-emitting diodes using a dynamic measurement technique. / Shi, J. W.; Kuo, F. M.; Lin, Che Wei; Chen, Wei; Yan, L. J.; Sheu, Jinn-Kong.

In: IEEE Photonics Technology Letters, Vol. 23, No. 21, 5983398, 21.10.2011, p. 1585-1587.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Investigation of the efficiency-droop mechanism in vertical red light-emitting diodes using a dynamic measurement technique

AU - Shi, J. W.

AU - Kuo, F. M.

AU - Lin, Che Wei

AU - Chen, Wei

AU - Yan, L. J.

AU - Sheu, Jinn-Kong

PY - 2011/10/21

Y1 - 2011/10/21

N2 - The mechanism responsible for the efficiency droop in AlGaInP-based vertically structured red light-emitting diodes (LEDs) is investigated using dynamic measurement techniques. Short electrical pulses (∼100 ps) are pumped into this device and the output optical pulses probed using high-speed photoreceiver circuits. From this, the internal carrier dynamic inside the device can be investigated by use of the measured electrical-to-optical (E-O) impulse responses. Results show that the E-O responses measured under different bias currents are all invariant from room temperature to ∼100 °C. This is contrary to most results reported for AlGaInP-based red LEDs, which usually exhibit a shortening in the response time and degradation in output power with the increase of ambient temperature. According to the extracted fall-time constants of the E-O impulse responses, the origin of the efficiency droop in our vertical LED structure, which has good heat-sinking, is not due to thermally induced carrier leakage, but rather should be attributed to defect recombination and the saturation of defect/spontaneous recombination processes under low and high bias current, respectively.

AB - The mechanism responsible for the efficiency droop in AlGaInP-based vertically structured red light-emitting diodes (LEDs) is investigated using dynamic measurement techniques. Short electrical pulses (∼100 ps) are pumped into this device and the output optical pulses probed using high-speed photoreceiver circuits. From this, the internal carrier dynamic inside the device can be investigated by use of the measured electrical-to-optical (E-O) impulse responses. Results show that the E-O responses measured under different bias currents are all invariant from room temperature to ∼100 °C. This is contrary to most results reported for AlGaInP-based red LEDs, which usually exhibit a shortening in the response time and degradation in output power with the increase of ambient temperature. According to the extracted fall-time constants of the E-O impulse responses, the origin of the efficiency droop in our vertical LED structure, which has good heat-sinking, is not due to thermally induced carrier leakage, but rather should be attributed to defect recombination and the saturation of defect/spontaneous recombination processes under low and high bias current, respectively.

UR - http://www.scopus.com/inward/record.url?scp=80054678711&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=80054678711&partnerID=8YFLogxK

U2 - 10.1109/LPT.2011.2164574

DO - 10.1109/LPT.2011.2164574

M3 - Article

VL - 23

SP - 1585

EP - 1587

JO - IEEE Photonics Technology Letters

JF - IEEE Photonics Technology Letters

SN - 1041-1135

IS - 21

M1 - 5983398

ER -