{"id":68271,"date":"2015-03-27T03:00:00","date_gmt":"2015-03-27T00:00:00","guid":{"rendered":"http:\/\/www.fyysika.ee\/?guid=24d6fde6f57d1656218334bce78f8b71"},"modified":"2015-03-27T03:00:00","modified_gmt":"2015-03-27T00:00:00","slug":"nobel-prize-for-blue-leds","status":"publish","type":"post","link":"https:\/\/www.fyysika.ee\/?p=68271","title":{"rendered":"Nobel Prize for blue LEDs"},"content":{"rendered":"<p>A brief review of lighting technologies is presented. Unavoidable restrictions for incandescent<br \/>\nlight bulbs caused by the Planck distribution and properties of the human eye are illustrated. The<br \/>\nefficiency and luminous efficacy of thermal radiation are calculated for various temperatures; the<br \/>\nresults clearly show the limitations for thermal radiators. The only way to overcome these<br \/>\nlimitations is using non-thermal radiators, such as fluorescent lamps and light-emitting diodes<br \/>\n(LEDs). Unique advantages of LEDs undoubtedly made a revolution in this field. A crucial element of<br \/>\nthis progress is the blue LEDs (Nobel Prize 2014). Some experiments with a blue and a green LED are<br \/>\ndescribed: (i) the luminescence triggered in a green-yellow phosphor inside a white LED by the blue<br \/>\nLED; (ii) radiant spectra and \u2018efficiency droop\u2019 in the LEDs; (iii) modulation of the blue LED up to<br \/>\n4 MHz; and (iv) the h \/ e ratio from the turn-on voltage of the green LED. The experiments are<br \/>\nsuita&#8230;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>A brief review of lighting technologies is presented. Unavoidable restrictions for incandescent<br \/>\nlight bulbs caused by the Planck distribution and properties of the human eye are illustrated. The<br \/>\nefficiency and luminous efficacy of thermal radiation a&#8230;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_genesis_hide_title":false,"_genesis_hide_breadcrumbs":false,"_genesis_hide_singular_image":false,"_genesis_hide_footer_widgets":false,"_genesis_custom_body_class":"","_genesis_custom_post_class":"","_genesis_layout":"","footnotes":""},"categories":[178],"tags":[],"class_list":{"0":"post-68271","1":"post","2":"type-post","3":"status-publish","4":"format-standard","6":"category-rss-fuusikaharidus","7":"entry"},"_links":{"self":[{"href":"https:\/\/www.fyysika.ee\/index.php?rest_route=\/wp\/v2\/posts\/68271","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.fyysika.ee\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.fyysika.ee\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.fyysika.ee\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.fyysika.ee\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=68271"}],"version-history":[{"count":0,"href":"https:\/\/www.fyysika.ee\/index.php?rest_route=\/wp\/v2\/posts\/68271\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.fyysika.ee\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=68271"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.fyysika.ee\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=68271"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.fyysika.ee\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=68271"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}