ترغب بنشر مسار تعليمي؟ اضغط هنا

Zinc Sulphide Overlayer Two-Dimensional Photonic Crystal for Enhanced Extraction of Light from a Micro Cavity Light-Emitting Diode

357   0   0.0 ( 0 )
 نشر من قبل Michael Mastro
 تاريخ النشر 2020
  مجال البحث فيزياء
والبحث باللغة English




اسأل ChatGPT حول البحث

A two-dimensional (2D) ZnS photonic crystal was deposited on the surface of a one-dimensional (1D) III-nitride micro cavity light-emitting diode (LED), to intermix the light extraction features of both structures (1D+2D). The deposition of an ideal micro-cavity optical thickness of lambda/2 is impractical for III-nitride LEDs, and in realistic multi-mode devices a large fraction of the light is lost to internal refraction as guided light. Therefore, a 2D photonic crystal on the surface of the LED was used to diffract and thus redirect this guided light out of the semiconductor over several hundred microns. Additionally, the employment of a post-epitaxy ZnS 2D photonic crystal avoided the typical etching into the GaN:Mg contact layer, a procedure which can cause damage to the near surface.



قيم البحث

اقرأ أيضاً

We report direct evidence of enhanced spontaneous emission in a photonic crystal (PhC) light-emitting diode. The device consists of p-i-n heterojunction embedded in a suspended membrane, comprising a layer of self-assembled quantum dots. Current is i njected laterally from the periphery to the center of the PhC. A well-isolated emission peak at 1300nm from the PhC cavity mode is observed, and the enhancement of the spontaneous emission rate is clearly evidenced by time-resolved electroluminescence measurements, showing that our diode switches off in a time shorter than the bulk radiative and nonradiative lifetimes
96 - Laszlo Frazer 2020
Artificial lighting is a widespread technology which consumes large amounts of energy. Triplet-triplet annihilation photochemical upconversion is a method of converting light to a higher frequency. Here, we show theoretically that photochemical upcon version can be applied to Watt-scale lighting, with performance closely approaching the 50% quantum yield upper limit. We describe the dynamic equilibrium of an efficient device consisting of an LED, an upconverting material, and an optical cavity from optical and thermal perspectives.
Silver nanoparticles dispersed on the surface of an inverted GaN LED were found to plasmonically enhance the near-bandedge emission. The resonant surface plasmon coupling led to a significant enhancement in the exciton decay rate and the ensemble of nanoparticles provided a mechanism to scatter the coupled energy as free space radiation. The inverted LED structure employed a tunnel junction to avoid the standard thick p+ GaN current spreading contact layer. In contrast to a standard design, the top contact was a thin n++ AlGaN layer, which brought the quantum well into the fringing field of the silver nanoparticles. This proximity allowed the excitons induced within the quantum well to couple to the surface plasmons, which in turn led to the enhanced band edge emission from the LED.
We present results on electrically driven nanobeam photonic crystal cavities formed out of a lateral p-i-n junction in gallium arsenide. Despite their small conducting dimensions, nanobeams have robust electrical properties with high current densitie s possible at low drive powers. Much like their two-dimensional counterparts, the nanobeam cavities exhibit bright electroluminescence at room temperature from embedded 1,250 nm InAs quantum dots. A small room temperature differential gain is observed in the cavities with minor beam self-heating suggesting that lasing is possible. These results open the door for efficient electrical control of active nanobeam cavities for diverse nanophotonic applications.
The enhancement of the power conversion efficiency (PCE), and subsequent reduction of cost, of light emitting diodes (LEDs) is of crucial importance in the current lightening market. For this reason, we propose here a PCE-enhanced LED architecture, b ased on a partially reflecting metasurface cavity (PRMC) structure. This structure simultaneously enhances the light extraction efficiency (LEE) and the spontaneous emission rate (SER) of the LED by enforcing the emitted light to radiate perpendicularly to the device, so as to suppress wave trapping and enhance field confinement near the emitter, while ensuring cavity resonance matching and maximal constructive field interference. The PRMC structure is designed using a recent surface susceptibility metasurface synthesis technique. A PRMC blue LED design is presented and demonstrated by full-wave simulation to provide LEE and SER enhancements by factors 4.0 and 1.9, respectively, which correspond to PCE enhancement factors of 6.2, 5.2 and 4.5 for IQEs of 0.25, 0.5 and 0.75, respectively, suggesting that the PRMC concept has a promising potential in LED technology.
التعليقات
جاري جلب التعليقات جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
mircosoft-partner

هل ترغب بارسال اشعارات عن اخر التحديثات في شمرا-اكاديميا