Presentation
20 April 2017 High modulation bandwidth of a light-emitting diode with surface plasmon coupling (Conference Presentation)
Chun-Han Lin, Charng-Gan Tu, Yu-Feng Yao, Sheng-Hung Chen, Chia-Ying Su, Hao-Tsung Chen, Yean-Woei Kiang, Chih-Chung Yang
Author Affiliations +
Abstract
Besides lighting, LEDs can be used for indoor data transmission. Therefore, a large modulation bandwidth becomes an important target in the development of visible LED. In this regard, enhancing the radiative recombination rate of carriers in the quantum wells of an LED is a useful method since the modulation bandwidth of an LED is related to the carrier decay rate besides the device RC time constant To increase the carrier decay rate in an LED without sacrificing its output power, the technique of surface plasmon (SP) coupling in an LED is useful. In this paper, the increases of modulation bandwidth by reducing mesa size, decreasing active layer thickness, and inducing SP coupling in blue- and green-emitting LEDs are illustrated. The results are demonstrated by comparing three different LED surface structures, including bare p-type surface, GaZnO current spreading layer, and Ag nanoparticles (NPs) for inducing SP coupling. In a single-quantum-well, blue-emitting LED with a circular mesa of 10 microns in radius, SP coupling results in a modulation bandwidth of 528.8 MHz, which is believed to be the record-high level. A smaller RC time constant can lead to a higher modulation bandwidth. However, when the RC time constant is smaller than ~0.2 ns, its effect on modulation bandwidth saturates. The dependencies of modulation bandwidth on injected current density and carrier decay time confirm that the modulation bandwidth is essentially inversely proportional to a time constant, which is inversely proportional to the square-root of carrier decay rate and injected current density.
Conference Presentation
© (2017) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Chun-Han Lin, Charng-Gan Tu, Yu-Feng Yao, Sheng-Hung Chen, Chia-Ying Su, Hao-Tsung Chen, Yean-Woei Kiang, and Chih-Chung Yang "High modulation bandwidth of a light-emitting diode with surface plasmon coupling (Conference Presentation)", Proc. SPIE 10124, Light-Emitting Diodes: Materials, Devices, and Applications for Solid State Lighting XXI, 101240M (20 April 2017); https://doi.org/10.1117/12.2249539
Advertisement
Advertisement
KEYWORDS
Light emitting diodes

Modulation

Surface plasmons

Nanoparticles

Data transmission

Light sources and illumination

Quantum wells

Back to Top