Researchers at the University of Hong Kong have demonstrated dynamic wavelength tuning in an InGaN/GaN field-effect LED (FE-LED), while maintaining a stable optical output.
Published in ACS Photonics, the study combines optical, structural and electrical characterization of a 50 μm-diameter device. The work was carried out using an Attolight Allalin system integrated with our flexible nanoprobing system, enabling electrical testing within the microscopy workflow.
Wavelength tuning with stable optical output
One of the key results is the ability to shift the device’s electroluminescence peak from 599 nm to 588 nm by applying a 40 V field voltage at a constant injection current of 0.5 mA.
At the same time, the normalized electroluminescence intensity remained within 10.6% variation, demonstrating wavelength tuning with relatively stable optical output.
The authors highlight potential applications in technologies requiring dynamically controlled, multiwavelength light sources, including on-chip photonic systems and micro-LED displays.
Adding electrical characterization to microscopy
This work also illustrates an important part of our approach to nanoprobing. Our expertise goes beyond developing precise electrical probing solutions. We specialize in integrating nanoprobing into microscopy and in-situ characterization techniques, enabling researchers to add electrical testing to the metrology techniques they already rely on.
In this case, our probers are integrated into the Attolight Allalin system, bringing accurately positioned electrical probing to a workflow that combines SEM, cathodoluminescence and electroluminescence characterization. This type of integration makes it possible to bring electrical information together with optical and structural information from the device under investigation, helping researchers build a more complete picture of its behaviour. This is the principle behind our work with instrument manufacturers: adapting and integrating nanoprobing to complement the primary microscopy or in-situ technique, rather than working as a separate measurement step.
We are pleased to see our nanoprobing technology contributing to this work from the University of Hong Kong and to continue our collaboration with Attolight on integrated characterization solutions for advanced optoelectronic devices.
Read the open-access paper: