Photoelectrochemical liftoff of LEDs grown on freestanding c-plane GaN substrates

David Hwang, Benjamin P. Yonkee, Burhan Saif Addin, Robert M. Farrell, Shuji Nakamura, James S. Speck, Steven DenBaars

Research output: Contribution to journalArticlepeer-review

38 Scopus citations


We demonstrate a thin-film flip-chip (TFFC) process for LEDs grown on freestanding c-plane GaN substrates. LEDs are transferred from a bulk GaN substrate to a sapphire submount via a photoelectrochemical (PEC) undercut etch. This PEC liftoff method allows for substrate reuse and exposes the N-face of the LEDs for additional roughening. The LEDs emitted at a wavelength of 432 nm with a turn on voltage of ~3 V. Etching the LEDs in heated KOH after transferring them to a sapphire submount increased the peak external quantum efficiency (EQE) by 42.5% from 9.9% (unintentionally roughened) to 14.1% (intentionally roughened).
Original languageEnglish (US)
Pages (from-to)22875
JournalOptics Express
Issue number20
StatePublished - Sep 23 2016
Externally publishedYes

Bibliographical note

KAUST Repository Item: Exported on 2020-10-01
Acknowledgements: KACST-KAUST-UCSB Solid State Lighting Program (SSLP) and the Solid State Lighting & Energy Electronics Center (SSLEEC); National Science Foundation (NSF) National Nanotechnology Infrastructure Network (NNIN) (ECS-0335765); UCSB MRL, supported by the NSF MRSEC Program (DMR05-20415). D. H. was supported by the National Science Foundation Graduate Research Fellowship under Grant No. DGE-1144085.
This publication acknowledges KAUST support, but has no KAUST affiliated authors.


Dive into the research topics of 'Photoelectrochemical liftoff of LEDs grown on freestanding c-plane GaN substrates'. Together they form a unique fingerprint.

Cite this