Investigating the Efficiency Droop of Nitride-Based Blue LEDs with Different Quantum Barrier Growth Rates

Growth of III-nitride quantum dots and their applications to blue-green LEDs

Efficiency droop in nitride-based light-emitting diodes

Nitride-based light-emitting diodes (LEDs) suffer from a reduction (droop) of the internal quantum efficiency with increasing injection current. This droop phenomenon is currently the subject of intense research worldwide, as it delays general lighting applications of GaN-based LEDs. Several explanations of the efficiency droop have been proposed in recent years, but none is widely accepted. Th...

Investigation of Efficiency Droop for InGaN-based LEDs with Carrier Localization State and Polarization Effect

We prepared wavelength-dependent InGaN-based light emitting diodes (LEDs) with peak emissions ranging from 400 to 445 nm, and investigated their efficiency droop characteristics at injection currents of up to 1 A. We found that the emissions of the wavelength-dependent InGaN LEDs underwent blue shifts at elevated currents. In addition, although the external quantum efficiencies (EQEs) changed d...

Optimisation of GaN LEDs and the reduction of efficiency droop using active machine learning

A fundamental challenge in the design of LEDs is to maximise electro-luminescence efficiency at high current densities. We simulate GaN-based LED structures that delay the onset of efficiency droop by spreading carrier concentrations evenly across the active region. Statistical analysis and machine learning effectively guide the selection of the next LED structure to be examined based upon its ...

the evaluation of language related engagment and task related engagment with the purpose of investigating the effect of metatalk and task typology

abstract while task-based instruction is considered as the most effective way to learn a language in the related literature, it is oversimplified on various grounds. different variables may affect how students are engaged with not only the language but also with the task itself. the present study was conducted to investigate language and task related engagement on the basis of the task typolog...