{"id":254,"date":"2022-01-05T13:48:40","date_gmt":"2022-01-05T05:48:40","guid":{"rendered":"https:\/\/www.eee.hku.hk\/microLED\/?p=254"},"modified":"2022-01-05T13:48:41","modified_gmt":"2022-01-05T05:48:41","slug":"analysis-of-micro-lens-integrated-flip-chip-ingan-light-emitting-diodes-by-confocal-microscopy","status":"publish","type":"post","link":"https:\/\/www.eee.hku.hk\/microLED\/analysis-of-micro-lens-integrated-flip-chip-ingan-light-emitting-diodes-by-confocal-microscopy\/","title":{"rendered":"Analysis of micro-lens integrated flip-chip InGaN light-emitting diodes by confocal microscopy"},"content":{"rendered":"\n<p class=\"has-text-align-right wp-block-paragraph\">&#8211; <em>KH Li, C Feng, and HW Choi<\/em><\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"727\" src=\"https:\/\/www.eee.hku.hk\/microLED\/wp-content\/uploads\/2022\/01\/1.4863925.figures.f1-1024x727.jpeg\" alt=\"\" class=\"wp-image-255\" srcset=\"https:\/\/www.eee.hku.hk\/microLED\/wp-content\/uploads\/2022\/01\/1.4863925.figures.f1-1024x727.jpeg 1024w, https:\/\/www.eee.hku.hk\/microLED\/wp-content\/uploads\/2022\/01\/1.4863925.figures.f1-300x213.jpeg 300w, https:\/\/www.eee.hku.hk\/microLED\/wp-content\/uploads\/2022\/01\/1.4863925.figures.f1-768x546.jpeg 768w, https:\/\/www.eee.hku.hk\/microLED\/wp-content\/uploads\/2022\/01\/1.4863925.figures.f1-1536x1091.jpeg 1536w, https:\/\/www.eee.hku.hk\/microLED\/wp-content\/uploads\/2022\/01\/1.4863925.figures.f1-422x300.jpeg 422w, https:\/\/www.eee.hku.hk\/microLED\/wp-content\/uploads\/2022\/01\/1.4863925.figures.f1.jpeg 2030w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><figcaption>Schematic diagram depicting the flip-chip LED with a micro-lens array on the sapphire surface; (b) AFM and (c) SEM images showing the hemispherical lens array.<\/figcaption><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\"><strong><em>Applied Physics Letters, vol. 104, 5, pp. 051107 (2014)<\/em><\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A hexagonally close-packed microlens array has been integrated onto the sapphire face of a flip-chip bonded InGaN light-emitting diode (LED). The micro-optics is formed by etching a self-assembled monolayer of 1-\u03bcm silica microspheres coated on the sapphire substrate, producing hemispherical sapphire lenses. Without degrading electrical characteristic, the light output power of the lensed LED is increased by more than a quarter compared with the unlensed LED. Enhanced light extraction via micro-optics is verified by rigorous coupled wave analysis. The focusing behavior of the micro-lenses, as well as the emission characteristics of the lensed LED, is studied by confocal microscopy.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">DOI:<a href=\"https:\/\/doi.org\/10.1109\/LED.2004.826541\" data-type=\"URL\" data-id=\"https:\/\/doi.org\/10.1109\/LED.2004.826541\"> <\/a><a rel=\"noreferrer noopener\" href=\"https:\/\/doi.org\/10.1088\/0957-4484\/19\/25\/255302\" data-type=\"URL\" data-id=\"https:\/\/doi.org\/10.1088\/0957-4484\/19\/25\/255302\" target=\"_blank\"><\/a><a href=\"https:\/\/doi-org.eproxy.lib.hku.hk\/10.1088\/0957-4484\/19\/35\/355203\" data-type=\"URL\" data-id=\"https:\/\/doi-org.eproxy.lib.hku.hk\/10.1088\/0957-4484\/19\/35\/355203\"><\/a><a href=\"https:\/\/doi.org\/10.1109\/JPHOT.2009.2020963\" data-type=\"URL\" data-id=\"https:\/\/doi.org\/10.1109\/JPHOT.2009.2020963\"><\/a><a rel=\"noreferrer noopener\" href=\"https:\/\/doi.org\/10.1364\/OE.17.009873\" data-type=\"URL\" data-id=\"https:\/\/doi.org\/10.1364\/OE.17.009873\" target=\"_blank\"><\/a><a href=\"https:\/\/doi.org\/10.1109\/LPT.2009.2022751\" data-type=\"URL\" data-id=\"https:\/\/doi.org\/10.1109\/LPT.2009.2022751\"><\/a><a href=\"https:\/\/doi.org\/10.1063\/1.4863925\" data-type=\"URL\" data-id=\"https:\/\/doi.org\/10.1063\/1.4863925\" target=\"_blank\" rel=\"noreferrer noopener\">10.1063\/1.4863925<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>&#8211; KH Li, C Feng, and HW Choi Applied Physics Letters, vol. 104, 5, pp. 051107 (2014) A hexagonally close-packed microlens array has been integrated&hellip;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3],"tags":[12,6,8],"class_list":["post-254","post","type-post","status-publish","format-standard","hentry","category-publications","tag-led","tag-light-extraction","tag-monolithic"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/www.eee.hku.hk\/microLED\/wp-json\/wp\/v2\/posts\/254","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.eee.hku.hk\/microLED\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.eee.hku.hk\/microLED\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.eee.hku.hk\/microLED\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.eee.hku.hk\/microLED\/wp-json\/wp\/v2\/comments?post=254"}],"version-history":[{"count":1,"href":"https:\/\/www.eee.hku.hk\/microLED\/wp-json\/wp\/v2\/posts\/254\/revisions"}],"predecessor-version":[{"id":256,"href":"https:\/\/www.eee.hku.hk\/microLED\/wp-json\/wp\/v2\/posts\/254\/revisions\/256"}],"wp:attachment":[{"href":"https:\/\/www.eee.hku.hk\/microLED\/wp-json\/wp\/v2\/media?parent=254"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.eee.hku.hk\/microLED\/wp-json\/wp\/v2\/categories?post=254"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.eee.hku.hk\/microLED\/wp-json\/wp\/v2\/tags?post=254"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}