Thin-film flip-chip UVB LEDs realized by electrochemical etching
Journal article, 2020

We demonstrate a thin-film flip-chip (TFFC) light-emitting diode (LED) emitting in the ultraviolet B (UVB) at 311 nm, where substrate removal has been achieved by electrochemical etching of a sacrificial Al0.37Ga0.63N layer. The electroluminescence spectrum of the TFFC LED corresponds well to the as-grown LED structure, showing no sign of degradation of structural and optical properties by electrochemical etching. This is achieved by a proper epitaxial design of the sacrificial layer and the etch stop layers in relation to the LED structure and the electrochemical etch conditions. Enabling a TFFC UV LED is an important step toward improving the light extraction efficiency that limits the power conversion efficiency in AlGaN-based LEDs.


Light-emitting diode


Electrochemical etching


Michael Alexander Bergmann

Chalmers, Microtechnology and Nanoscience (MC2), Photonics

Johannes Enslin

Technische Universität Berlin

Filip Hjort

Chalmers, Microtechnology and Nanoscience (MC2), Photonics

Tim Wernicke

Technische Universität Berlin

Michael Kneissl

Technische Universität Berlin

Åsa Haglund

Chalmers, Microtechnology and Nanoscience (MC2), Photonics

Applied Physics Letters

0003-6951 (ISSN) 1077-3118 (eISSN)

Vol. 116 12 121101-

Areas of Advance

Nanoscience and Nanotechnology (2010-2017)

Subject Categories

Other Physics Topics

Nano Technology

Condensed Matter Physics


Chalmers Materials Analysis Laboratory

Nanofabrication Laboratory



More information

Latest update