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 language | English |
|---|---|
| Article number | 5983398 |
| Pages (from-to) | 1585-1587 |
| Number of pages | 3 |
| Journal | IEEE Photonics Technology Letters |
| Volume | 23 |
| Issue number | 21 |
| DOIs | |
| Publication status | Published - 2011 Oct 21 |
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All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Atomic and Molecular Physics, and Optics
- Electrical and Electronic Engineering
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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 journal › Article
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.
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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 -