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arXiv · 1512.02260

Enhanced Light Extraction in Tunnel Junction Enabled Top Emitting UV LEDs

Yuewei Zhang·Andrew Allerman·Sriram Krishnamoorthy·Fatih Akyol·Michael W. Moseley·Andrew Armstrong·Siddharth Rajan
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Abstract

The efficiency of ultra violet LEDs is critically limited by the absorption losses in p-type and metal layers. In this work, surface roughening based light extraction structures are combined with tunneling-based top-contacts to realize highly efficient top-side light extraction efficiency in UV LEDs. Surface roughening of the top n-type AlGaN contact layer is demonstrated using self-assembled Ni nano-clusters as etch mask. The top surface roughened LEDs were found to enhance external quantum efficiency by over 40% for UV LEDs with a peak emission wavelength of 326 nm. The method described here can enable highly efficient UV LEDs without the need for complex manufacturing methods such as flip chip bonding.

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Yuewei Zhang, Andrew Allerman, Sriram Krishnamoorthy, Fatih Akyol, Michael W. Moseley, Andrew Armstrong, Siddharth Rajan. 2015-12-07. Enhanced Light Extraction in Tunnel Junction Enabled Top Emitting UV LEDs. https://doi.org/10.7567/apex.9.052102

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