Electroluminescence hyperspectral imaging of light-emitting diodes using a liquid crystal tunable filter

Edwards, Paul R. and Bruckbauer, Jochen and Cameron, Douglas and Martin, Robert W. (2023) Electroluminescence hyperspectral imaging of light-emitting diodes using a liquid crystal tunable filter. Applied Physics Letters, 123 (11). 112110. ISSN 0003-6951 (https://doi.org/10.1063/5.0165060)

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Abstract

We demonstrate the use of a low-cost liquid-crystal-based wavelength-tunable filter and CMOS video camera to add hyperspectral imaging capabilities to a probe station equipped with a simple optical microscope. The resultant setup is used to rapidly resolve the spectral and spatial variations in electroluminescence typically observed for InxGa1−xN/GaN light-emitting diodes. Applying standard statistical analyses of variation within the multivariate datasets, such as moments and principal components, we observe inhomogeneities on a spectral scale significantly smaller than the bandwidth of the tunable filter. The resultant tool offers an alternative to scanning beam luminescence techniques for high-throughput hyperspectral analysis of optoelectronic devices.

ORCID iDs

Edwards, Paul R. ORCID logoORCID: https://orcid.org/0000-0001-7671-7698, Bruckbauer, Jochen ORCID logoORCID: https://orcid.org/0000-0001-9236-9320, Cameron, Douglas and Martin, Robert W. ORCID logoORCID: https://orcid.org/0000-0002-6119-764X;