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Title: Semiconductor light-emitting devices having concave microstructures providing improved light extraction efficiency and method for producing same

Abstract

A conventional semiconductor LED is modified to include a microlens layer over its light-emitting surface. The LED may have an active layer including at least one quantum well layer of InGaN and GaN. The microlens layer includes a plurality of concave microstructures that cause light rays emanating from the LED to diffuse outwardly, leading to an increase in the light extraction efficiency of the LED. The concave microstructures may be arranged in a substantially uniform array, such as a close-packed hexagonal array. The microlens layer is preferably constructed of curable material, such as polydimethylsiloxane (PDMS), and is formed by soft-lithography imprinting by contacting fluid material of the microlens layer with a template bearing a monolayer of homogeneous microsphere crystals, to cause concave impressions, and then curing the material to fix the concave microstructures in the microlens layer and provide relatively uniform surface roughness.

Inventors:
; ; ;
Issue Date:
Research Org.:
Lehigh University, Bethlehem, PA, USA
Sponsoring Org.:
USDOE
OSTI Identifier:
1108717
Patent Number(s):
8,586,963
Application Number:
12/963,098
Assignee:
Lehigh University (Bethlehem, PA)
DOE Contract Number:  
FC26-08NT01581
Resource Type:
Patent
Country of Publication:
United States
Language:
English
Subject:
42 ENGINEERING

Citation Formats

Tansu, Nelson, Gilchrist, James F, Ee, Yik-Khoon, and Kumnorkaew, Pisist. Semiconductor light-emitting devices having concave microstructures providing improved light extraction efficiency and method for producing same. United States: N. p., 2013. Web.
Tansu, Nelson, Gilchrist, James F, Ee, Yik-Khoon, & Kumnorkaew, Pisist. Semiconductor light-emitting devices having concave microstructures providing improved light extraction efficiency and method for producing same. United States.
Tansu, Nelson, Gilchrist, James F, Ee, Yik-Khoon, and Kumnorkaew, Pisist. Tue . "Semiconductor light-emitting devices having concave microstructures providing improved light extraction efficiency and method for producing same". United States. https://www.osti.gov/servlets/purl/1108717.
@article{osti_1108717,
title = {Semiconductor light-emitting devices having concave microstructures providing improved light extraction efficiency and method for producing same},
author = {Tansu, Nelson and Gilchrist, James F and Ee, Yik-Khoon and Kumnorkaew, Pisist},
abstractNote = {A conventional semiconductor LED is modified to include a microlens layer over its light-emitting surface. The LED may have an active layer including at least one quantum well layer of InGaN and GaN. The microlens layer includes a plurality of concave microstructures that cause light rays emanating from the LED to diffuse outwardly, leading to an increase in the light extraction efficiency of the LED. The concave microstructures may be arranged in a substantially uniform array, such as a close-packed hexagonal array. The microlens layer is preferably constructed of curable material, such as polydimethylsiloxane (PDMS), and is formed by soft-lithography imprinting by contacting fluid material of the microlens layer with a template bearing a monolayer of homogeneous microsphere crystals, to cause concave impressions, and then curing the material to fix the concave microstructures in the microlens layer and provide relatively uniform surface roughness.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {2013},
month = {11}
}

Patent:

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