6 February 2012 Study of efficiency-droop mechanism in vertical red light-emitting diodes using electrical-to-optical impulse responses
Author Affiliations +
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 (~100ps) are pumped into this device and the output optical pulses probed using high-speed photo-receiver 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°. 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 these measurement results and 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 spontaneous recombination processes.
© (2012) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
J.-W. Shi, F.-M. Kuo, Che-Wei Lin, Wei Chen, M. L. Lee, L.-J. Yan, J.-K. Sheu, "Study of efficiency-droop mechanism in vertical red light-emitting diodes using electrical-to-optical impulse responses", Proc. SPIE 8278, Light-Emitting Diodes: Materials, Devices, and Applications for Solid State Lighting XVI, 82781S (6 February 2012); doi: 10.1117/12.906990; https://doi.org/10.1117/12.906990
PROCEEDINGS
7 PAGES


SHARE
RELATED CONTENT


Back to Top