{"id":24837,"date":"2014-11-01T12:43:44","date_gmt":"2014-11-01T10:43:44","guid":{"rendered":"https:\/\/bilimvegelecek.com.tr\/?p=24837"},"modified":"2018-05-08T12:53:54","modified_gmt":"2018-05-08T09:53:54","slug":"nobel-fizik-odulunu-alan-calisma-21-yuzyili-aydinlatan-teknoloji-led-isik","status":"publish","type":"post","link":"https:\/\/bilimvegelecek.com.tr\/index.php\/2014\/11\/01\/nobel-fizik-odulunu-alan-calisma-21-yuzyili-aydinlatan-teknoloji-led-isik","title":{"rendered":"Nobel Fizik \u00d6d\u00fcl\u00fcn\u00fc alan \u00e7al\u0131\u015fma…\u00a021. y\u00fczy\u0131l\u0131 ayd\u0131nlatan teknoloji: LED \u0131\u015f\u0131k"},"content":{"rendered":"

Yar\u0131 iletkenlerden \u00fcretilen parlak mavi \u0131\u015f\u0131k at\u0131mlar\u0131, ayd\u0131nlatma teknolojisinde temel bir d\u00f6n\u00fc\u015f\u00fcm\u00fcn \u00f6nc\u00fcs\u00fc oldu. 20. y\u00fczy\u0131l\u0131 ayd\u0131nlatan akkor lambalar\u0131n yerine, art\u0131k daha g\u00fc\u00e7l\u00fc ve daha tasarruflu alternatif ayd\u0131nlatma arac\u0131na, LED \u0131\u015f\u0131\u011fa sahibiz.<\/em><\/p>\n

Bilindi\u011fi gibi, Nobel \u00d6d\u00fclleri, Alfred Nobel\u2019in vasiyeti \u00fczerine \u201cinsanl\u0131\u011fa b\u00fcy\u00fck katk\u0131\u201d sa\u011flad\u0131\u011f\u0131 d\u00fc\u015f\u00fcn\u00fclen bilimcilere \u0130sve\u00e7 Kraliyet Bilim Akademisi taraf\u0131ndan 1901 y\u0131l\u0131ndan bu yana verilmektedir.\u00a0 Modern fizi\u011fe b\u00fcy\u00fck katk\u0131lar\u0131 olan bir\u00e7ok \u00fcnl\u00fc fizik\u00e7inin de sahip oldu\u011fu \u00f6d\u00fcl, bu sene yar\u0131 iletken ve ayd\u0131nlatma teknolojisinde \u00e7\u0131\u011f\u0131r a\u00e7m\u0131\u015f \u00fc\u00e7 bilimciye verildi.<\/p>\n

2014 Nobel Fizik \u00d6d\u00fcl\u00fc, \u201cParlak ve enerji tasarruflu beyaz \u0131\u015f\u0131k kaynaklar\u0131na imk\u00e2n tan\u0131yan, y\u00fcksek verimli mavi \u0131\u015f\u0131k yayan diyotlar\u0131n icatlar\u0131<\/strong>\u201dndan dolay\u0131, Isamu Akasaki (Nagoya \u00dcniversitesi), Hiroshi Amano (Nagoya \u00dcniversitesi) ve Shuji Nakamura (Kaliforniya \u00dcniversitesi) aras\u0131nda payla\u015ft\u0131r\u0131ld\u0131.<\/p>\n

Nobel getiren bu icattan s\u00f6z a\u00e7madan \u00f6nce, yar\u0131 iletken diyotlardan k\u0131saca bahsetmek konunun anla\u015f\u0131labilirli\u011fi a\u00e7\u0131s\u0131ndan son derece faydal\u0131 olacakt\u0131r.<\/p>\n

\"\"Nobel Fizik \u00d6d\u00fcl\u00fc\u2019n\u00fc alan bilimciler<\/strong><\/p>\n

Isamu Akasaki<\/strong><\/p>\n

30 Ocak 1929\u2019da Chiran, Japonya\u2019da do\u011fdu. 1952\u2019de Kyoto \u00dcniv. Bilim Okulu\u2019ndan mezun oldu. 1959\u2019da Nagoya \u00dcniversitesi\u2019nde asistan olarak \u00e7al\u0131\u015fmaya ba\u015flayan Akasaki, 1964\u2019te ayn\u0131 \u00fcniversitede M\u00fchendislik Okulu\u2019ndan doktora derecesini ald\u0131. 1970\u2019lerin ba\u015f\u0131nda mavi LED geli\u015ftirme \u00e7al\u0131\u015fmalar\u0131na ba\u015flad\u0131 ve 1981\u2019de profes\u00f6r oldu. 1992\u2019de emekli olan Akasaki, \u015fu anda Meijo \u00dcniversitesi\u2019nde profes\u00f6r, Nagoya \u00dcniversitesi\u2019nde ise ayr\u0131cal\u0131kl\u0131 (ordinaryus) profes\u00f6r unvanlar\u0131na sahiptir.(1)<\/sup> 2014 Nobel Fizik \u00d6d\u00fcl\u00fc\u2019n\u00fcn yan\u0131 s\u0131ra, 2009\u2019da Kyoto \u00d6d\u00fcl\u00fc\u2019n\u00fc ve 2011\u2019de IEEE (Elektrik ve Elektronik M\u00fchendisleri Enstit\u00fcs\u00fc) Edison Madalyas\u0131\u2019n\u0131 alm\u0131\u015ft\u0131r.(2),(3)<\/sup><\/p>\n

Hiroshi Amano<\/strong><\/p>\n

11 Eyl\u00fcl 1960\u2019ta Hamamatsu, Japonya\u2019da do\u011fdu. 1982\u2019de lisans \u00f6\u011frencisiyken Isamu Akasaki\u2019nin \u00e7al\u0131\u015fma grubuna kat\u0131ld\u0131.(4) <\/sup>1983\u2019te Nagoya \u00dcniv. Elektronik M\u00fchendisli\u011fi B\u00f6l\u00fcm\u00fc\u2019nden lisans mezunu oldu. Doktora derecesini de 1989\u2019da ayn\u0131 b\u00f6l\u00fcmden alan Amano, 2002\u2019de Meijo \u00dcniversitesi\u2019nde profes\u00f6r olarak \u00e7al\u0131\u015fmaya ba\u015flad\u0131. 2010\u2019da Nagoya \u00dcniversitesi\u2019ne\u00a0 profes\u00f6r olarak\u00a0 geri d\u00f6nd\u00fc ve halen orada \u00e7al\u0131\u015fmaktad\u0131r.(5)<\/sup><\/p>\n

Shuji Nakamura<\/strong><\/p>\n

22 May\u0131s 1954\u2019te Ehime, Japonya\u2019da do\u011fdu. Tokushima \u00dcniv. Elektrik M\u00fchendisli\u011fi B\u00f6l\u00fcm\u00fc\u2019nden 1977\u2019de lisans; 1979\u2019da y\u00fcksek lisans derecelerini ald\u0131 ve ayn\u0131 y\u0131l Nichia Kimya\u2019da \u00e7al\u0131\u015fmaya ba\u015flad\u0131. 1989 y\u0131l\u0131nda mavi LED geli\u015ftirme \u00e7al\u0131\u015fmalar\u0131na ba\u015flad\u0131. 1994\u2019te doktora derecesini yine Tokushima \u00dcniversitesi\u2019nden alan Nakamura, 1999\u2019da \u00e7al\u0131\u015ft\u0131\u011f\u0131 firmay\u0131 b\u0131rakarak Kaliforniya \u00dcniversitesi\u2019nde profes\u00f6r olarak\u00a0 i\u015fe ba\u015flad\u0131. Halen Kaliforniya \u00dcniversitesi\u2019nde profes\u00f6rl\u00fck yapan Nakamura akademik hayat\u0131 boyunca bir\u00e7ok \u00f6d\u00fcl\u00fcn sahibi olmu\u015ftur.(6), (7) <\/sup><\/p>\n

Kaynaklar<\/strong><\/p>\n

1) http:\/\/en.nagoyau.ac.jp\/people\/distinguished_award_recipients\/nagoya_university_distinguished_professor_isamu_akasaki.html<\/p>\n

2) http:\/\/www.inamori-f.or.jp\/laureates\/k25_a_isamu\/ctn_e.html<\/p>\n

3) http:\/\/www.ieee.org\/documents\/edison_rl.pdf<\/p>\n

4) \u00a0http:\/\/en.wikipedia.org\/wiki\/Hiroshi_Amano<\/p>\n

5) http:\/\/profs.provost.nagoya-u.ac.jp\/view\/html\/100001778_en.html<\/p>\n

6) http:\/\/ssleec.ucsb.edu\/nakamura<\/p>\n

7) http:\/\/engineering.ucsb.edu\/faculty\/profile\/82<\/p><\/blockquote>\n

Yar\u0131 iletkenler<\/strong><\/p>\n

Kat\u0131larda atomlar aras\u0131 mesafeler olduk\u00e7a k\u00fc\u00e7\u00fckt\u00fcr. Bu durum, atomlar aras\u0131 etkile\u015fmeleri \u00f6nemli hale getirir. Ancak kat\u0131daki atomlar\u0131n birbirleriyle etkile\u015fimlerini incelemek yerine -ki pratikte imk\u00e2ns\u0131zd\u0131r- kat\u0131y\u0131 enerji bantlar\u0131ndan olu\u015fmu\u015f bir yap\u0131 olarak ele almak\u00a0 \u201ciletkenlik\u201d kavram\u0131n\u0131n anla\u015f\u0131lmas\u0131 a\u00e7\u0131s\u0131ndan olduk\u00e7a kullan\u0131\u015fl\u0131d\u0131r.<\/p>\n

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\u015eekil 1. Bant teorisine g\u00f6re yal\u0131tkan, yar\u0131 iletken ve iletken.(3)<\/figcaption><\/figure>\n

Kat\u0131lar\u0131n bant teorisinde ele al\u0131nan enerji bantlar\u0131ndan iletkenlik (conduction) band\u0131, iletkenli\u011fi sa\u011flayan serbest elektronlar\u0131n bulundu\u011fu enerji bant aral\u0131\u011f\u0131d\u0131r. Valans (de\u011ferlik) band\u0131 ise, atomlar\u0131n son y\u00f6r\u00fcngelerindeki elektronlar\u0131n bulundu\u011fu enerji bant aral\u0131\u011f\u0131d\u0131r. Valans band\u0131ndan iletkenlik band\u0131na ge\u00e7ebilen elektron, serbest hale ge\u00e7erek kat\u0131da iletkenli\u011fi sa\u011flar. Ancak iki bant aras\u0131nda a\u015f\u0131lmas\u0131 gereken bir enerji aral\u0131\u011f\u0131 vard\u0131r. Bu aral\u0131k \u201cyasak bant\u201d olarak adland\u0131r\u0131l\u0131r ve yasak bant\u0131n geni\u015fli\u011fi kat\u0131n\u0131n iletkenlik karakeristi\u011fini belirler.<\/p>\n

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Yar\u0131 iletken diyotun yap\u0131s\u0131.(4)<\/figcaption><\/figure>\n

\u015eekil 2\u2019de g\u00f6r\u00fcld\u00fc\u011f\u00fc \u00fczere iletkenlerde yasak bant aral\u0131\u011f\u0131 bulunmazken, yal\u0131tkanlarda bu aral\u0131k \u00e7ok fazlad\u0131r. Yar\u0131 iletkenlerde ise yasak aral\u0131k ikisinin aras\u0131nda bir de\u011ferdedir.<\/p>\n

Valans band\u0131ndan iletkenlik band\u0131na ge\u00e7i\u015fin d\u00fc\u015f\u00fck enerjilerle manip\u00fcle edilebilmesi, yar\u0131 iletkenleri elektronik teknolojisinde vazge\u00e7ilemez yapar.\u00a0 \u00c7ok\u00e7a bahsedildi\u011fi \u00fczere, dijital elektronik 1 ve 0\u2019lar \u00fczerine kuruludur. Bunun fiziksel anlam\u0131 ise olduk\u00e7a basittir: Ak\u0131m ge\u00e7irmek (1) ve ak\u0131m ge\u00e7irmemek (0). Diyot ad\u0131 verilen tek y\u00f6nl\u00fc ak\u0131m ge\u00e7irme \u00f6zelli\u011fine sahip elektronik ekipmanlar, bu \u00f6zelli\u011finden dolay\u0131 elektroni\u011fin en \u00f6nemli malzemesidir. Yar\u0131 iletken kullan\u0131larak tek y\u00f6nl\u00fc ak\u0131m ge\u00e7irme \u00f6zelli\u011fine sahip diyotlar\u0131n yap\u0131lmas\u0131yla birlikte dijital \u00e7a\u011f\u0131n kap\u0131lar\u0131 aralanm\u0131\u015f, bilgisayardan televizyonlara, telefonlardan LED\u2019lere modern elektronik cihazlar\u0131n \u00fcretimi olanakl\u0131 hale gelmi\u015ftir.<\/p>\n

Yar\u0131 iletkenler son y\u00f6r\u00fcngelerinde 4 elektron bulundurur. Germanyum ve silisyum elementleri gibi 4 de\u011ferlik elektronuna sahip saf bir yar\u0131 iletkendeki atomlar, di\u011fer kom\u015fu atomlarla kovalent ba\u011f yaparak kristal yap\u0131 olu\u015fturur ve malzeme yal\u0131tkan \u00f6zellik g\u00f6sterir. Yar\u0131 iletken diyotlar\u0131n elde edilmesinin yolu ise; bu t\u00fcrdeki saf maddelere \u00e7ok d\u00fc\u015f\u00fck oranlarda yap\u0131lacak yabanc\u0131 madde katk\u0131s\u0131n\u0131n yar\u0131 iletken maddeyi \u00f6zel bir hale getirmesiyle a\u00e7\u0131lm\u0131\u015ft\u0131r.<\/p>\n

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Mavi LED’in \u00e7al\u0131\u015fma prensibi.<\/figcaption><\/figure>\n

Saf germanyum ve silisyum elementlerine \u00e7ok d\u00fc\u015f\u00fck oranlarda yabanc\u0131 madde katk\u0131s\u0131 yap\u0131ld\u0131\u011f\u0131nda p-tipi ve n-tipi \u00f6zel yar\u0131 iletkenler elde edilebilir. Son y\u00f6r\u00fcngesinde 5 elektron bulunan bir madde (arsenik, fosfor, …) saf yar\u0131 iletkene katk\u0131land\u0131\u011f\u0131nda, 4 elektron maddeyle kovalent ba\u011f olu\u015fturur ve fazladan da 1 elektron madde i\u00e7inde serbest kal\u0131r. Elektron y\u00f6n\u00fcnden zengin olan bu t\u00fcr yar\u0131 iletkene \u201cn-tipi yar\u0131 iletken\u201d denir. Katk\u0131 maddesinin son y\u00f6r\u00fcngesinde 3 elektron oldu\u011funda (galyum, bor,…) ise, katk\u0131lanan maddenin elektronlar\u0131ndan biri kovalent ba\u011f yapamaz ve bir elektron bo\u015flu\u011fu olu\u015fur. Elektron y\u00f6n\u00fcnden yoksul olan bu kar\u0131\u015f\u0131mda elektrona ihtiya\u00e7 olan yer \u201cbo\u015fluk (hole)\u201d olarak adland\u0131r\u0131l\u0131r ve pozitif y\u00fckl\u00fc kabul edilebilir. Bo\u015fluk y\u00f6n\u00fcnden zengin katk\u0131l\u0131 yar\u0131 iletkenlere de \u201cp-tipi yar\u0131 iletken\u201d denir. p-tipi ve n-tipi yar\u0131 iletkenler birbirine eklemlendi\u011finde, eklem b\u00f6lgesinde n-tipinden gelen elektron ve p-tipinden gelen bo\u015fluklar iyonize atomlardan olu\u015fan deplesyon b\u00f6lgesi olu\u015fturur. Ters kutuplanma durumunda deplesyon b\u00f6lgesi geni\u015fler ve ak\u0131m olu\u015fmaz. Do\u011fru kutuplanma durumunda ise aktif b\u00f6lge daral\u0131r ve elektronlar aktif b\u00f6lgeyi ge\u00e7erek ak\u0131m olu\u015fturur. Kutuplanma durumuna g\u00f6re ak\u0131m\u0131n ge\u00e7ip ge\u00e7memesi de pn eklemli yar\u0131 iletken malzemenin diyot olarak \u00e7al\u0131\u015ft\u0131\u011f\u0131n\u0131 g\u00f6sterir.<\/p>\n

I\u015f\u0131k yayan diyot: LED<\/strong><\/p>\n

Yar\u0131 iletken diyotlardaki elektron-bo\u015fluk \u00e7iftlerinin elektriksel gerilim alt\u0131nda birle\u015ferek \u0131\u015f\u0131ma yapmas\u0131yla do\u011fan LED teknolojisi, ad\u0131n\u0131 \u201clight emitting diode\u201d kelimelerinin ba\u015fharflerinden al\u0131r. LED\u2019in temel \u00e7al\u0131\u015fma prensibi, elektriksel gerilim alt\u0131nda p-tipi tabakadaki bo\u015fluklar\u0131n n-tipi tabakadaki elektronlarla birle\u015fip \u0131\u015f\u0131ma yapmas\u0131na dayan\u0131r.<\/p>\n

Yar\u0131 iletkenden \u0131\u015f\u0131k yay\u0131ld\u0131\u011f\u0131na dair ilk rapor, 1909 Nobel Fizik \u00d6d\u00fcll\u00fc, \u201ckablosuz telegraf\u00e7\u0131l\u0131\u011f\u0131n geli\u015fimine katk\u0131lar\u0131ndan dolay\u0131\u201d K. F. Braun ile birlikte \u00f6d\u00fcl alan Guglielmo Marconi\u2019nin asistan\u0131 Henry J. Round taraf\u0131ndan haz\u0131rlanm\u0131\u015ft\u0131r. Daha sonra 1920\u2019li 1930\u2019lu y\u0131llarda da \u0131\u015f\u0131k yay\u0131n\u0131m\u0131na dair ileri \u00e7al\u0131\u015fmalar Sovyetler Birli\u011fi\u2019nden Oleg V. Losev taraf\u0131ndan s\u00fcrd\u00fcr\u00fclm\u00fc\u015f, fakat fenomenin arkas\u0131nda yatan teori yeterince anla\u015f\u0131lamad\u0131\u011f\u0131ndan \u201celektro\u0131\u015f\u0131ma (electroluminescence)\u201d alan\u0131n\u0131n ortaya \u00e7\u0131kmas\u0131 birka\u00e7 on y\u0131l gecikmi\u015ftir.<\/p>\n

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K\u0131rm\u0131z\u0131 ve ye\u015fil LED \u00fcretimi 1950\u2019lerin sonlar\u0131na rastlar. Dijital saatlerde ve hesap makinelerinde a\u00e7ma-kapama g\u00f6stergelerinde kullan\u0131lan LED, her ne kadar b\u00fcy\u00fck bir icat olsa da ayd\u0131nlatmada kullan\u0131lacak \u0131\u015f\u0131\u011f\u0131n rengi beyaz olmal\u0131d\u0131r. Beyaz LED lambalar ise iki farkl\u0131 yoldan \u00fcretilebilir: Birincisi, mavi \u0131\u015f\u0131\u011f\u0131 fosfor \u00fczerine g\u00f6nderip k\u0131rm\u0131z\u0131 ve ye\u015fil renklerde \u0131\u015f\u0131ma yapmas\u0131n\u0131 sa\u011flamak. B\u00f6ylece \u00fc\u00e7 renk bir araya getirilip beyaz \u0131\u015f\u0131k olu\u015fturulabilir. Di\u011fer yol i\u015fi g\u00f6ze b\u0131rakarak k\u0131rm\u0131z\u0131, ye\u015fil ve mavi LED\u2019leri bir lambaya koymakla sa\u011flan\u0131r. \u0130nsan g\u00f6z\u00fc bu \u00fc\u00e7 rengin kombinasyonunu beyaz olarak g\u00f6r\u00fcr. Her iki durumda da mavi LED\u2019in \u00fcretilmesi gerekti\u011fi a\u015fik\u00e2rd\u0131r.<\/p>\n

Mavi LED\u2019in gereklili\u011fi bir\u00e7ok ara\u015ft\u0131rmac\u0131y\u0131 bu \u00e7al\u0131\u015fmaya y\u00f6nlendirse de, t\u00fcm u\u011fra\u015flar 2014 Nobel Fizik \u00d6d\u00fcl\u00fc\u2019ne lay\u0131k g\u00f6r\u00fclen \u00fc\u00e7 bilimciye dek bo\u015fa \u00e7\u0131km\u0131\u015ft\u0131r.(5) <\/sup><\/p>\n

Ayd\u0131nlatmaya giden yol: Mavi LED<\/strong><\/p>\n

1986 y\u0131l\u0131nda, Nagoya \u00dcniversitesi\u2019nde \u00e7al\u0131\u015fan Isamu Akasaki ve \u00f6\u011frencisi Hiroshi Amano, safir alt tabakan\u0131n \u00fczerine al\u00fcminyum nitrit tabakas\u0131 yerle\u015ftirdikten sonra, \u00fczerini y\u00fcksek kalite galyum nitritle kaplayarak, y\u00fcksek kalitede galyum nitrit kristali elde etmeyi ba\u015farm\u0131\u015flard\u0131r. Birka\u00e7 y\u0131l sonra da p-tipi tabaka elde etme yolunda b\u00fcy\u00fck at\u0131l\u0131m yapt\u0131lar. Tesad\u00fcfen, malzemelerin elektron tarama mikroskobuyla incelendi\u011finde daha g\u00fc\u00e7l\u00fc parlad\u0131\u011f\u0131n\u0131 g\u00f6zlemleyerek mikroskoptan gelen elektronik at\u0131mlar\u0131n p-tipi tabakay\u0131 daha etkili hale getirdi\u011fini anlad\u0131lar ve 1992 y\u0131l\u0131nda ilk parlak mavi \u0131\u015f\u0131k yayan diyotu bilim camias\u0131na sundular.<\/p>\n

Tokushima\u2019da bir kimya \u015firketinde \u00e7al\u0131\u015fan Shuji Nakamura ise, mavi LED geli\u015ftirme \u00e7al\u0131\u015fmalar\u0131na 1988 y\u0131l\u0131nda ba\u015flad\u0131. \u0130ki y\u0131l i\u00e7inde y\u00fcksek kalite galyum nitrit elde etmeyi ba\u015faran Nakamura, ince tabaka galyum nitriti d\u00fc\u015f\u00fck s\u0131cakl\u0131kta; alt tabakay\u0131 ise y\u00fcksek s\u0131cakl\u0131kta kaplayarak zekice bir metodla kristal elde etti.<\/p>\n

Nakamura ayn\u0131 zamanda Akasaki ve Amano\u2019nun p-tipi tabakalar\u0131n\u0131n nas\u0131l ba\u015far\u0131l\u0131 oldu\u011funu da a\u00e7\u0131klayabiliyordu. Ona g\u00f6re mikroskoptan gelen elektron at\u0131mlar\u0131 p-tipi tabakan\u0131n olu\u015fmas\u0131na engel olan hidrojeni ortadan kald\u0131r\u0131yor, b\u00f6ylece tabaka olu\u015fturulabiliyordu. Elektron mikroskobunun \u00e7\u00f6z\u00fcmdeki g\u00f6revini anlayan Nakamura, elektron at\u0131mlar\u0131yla ayn\u0131 i\u015flevi g\u00f6recek daha ucuz ve daha basit bir metot ortaya koydu. Malzemeyi \u0131s\u0131tan Nakamura, 1992\u2019de fonksiyonel p-tipi tabaka elde etmeyi ba\u015fard\u0131. Bu haliyle Nakamura\u2019n\u0131n \u00e7\u00f6z\u00fcm\u00fc Akasaki ve Amano\u2019nun \u00e7\u00f6z\u00fcmlerinden farkl\u0131yd\u0131.<\/p>\n

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LED lamban\u0131n ayd\u0131nlatma g\u00fcc\u00fc.(5)<\/figcaption><\/figure>\n

Doksanl\u0131 y\u0131llar boyunca iki \u00e7al\u0131\u015fma grubu da \u00fcrettikleri mavi LED\u2019i geli\u015ftirdi. Galyum nitritin al\u00fcminyum ve indiyum ile \u00e7e\u015fitli ala\u015f\u0131mlar\u0131 kullan\u0131larak LED teknolojisine gitgide daha kompleks bir yap\u0131 kazand\u0131r\u0131ld\u0131.(5)<\/sup><\/p>\n

\u0130nsanl\u0131\u011fa b\u00fcy\u00fck katk\u0131<\/strong><\/p>\n

Isamu Akasaki, Hiroshi Amano ve Shuji Nakamura 1990\u2019lar\u0131n ba\u015f\u0131nda yar\u0131 iletkenlerinden \u00fcrettikleri parlak mavi \u0131\u015f\u0131k at\u0131mlar\u0131yla, ayd\u0131nlatma teknolojisinde temel bir d\u00f6n\u00fc\u015f\u00fcm\u00fcn \u00f6nc\u00fcleri oldular. 20. y\u00fczy\u0131l\u0131 ayd\u0131nlatan akkor lambalar\u0131n yerine art\u0131k daha g\u00fc\u00e7l\u00fc ve daha tasarruflu alternatif ayd\u0131nlatma ara\u00e7lar\u0131na sahibiz. LED \u0131\u015f\u0131k, s\u00fcrekli daha verimli hale getiriliyor. \u015eu anki rekoru 300 lm\/W (birim elekriksel g\u00fc\u00e7 ba\u015f\u0131na d\u00fc\u015fen ayd\u0131nl\u0131k ak\u0131) olan beyaz LED\u2019lerin verimlili\u011fi, beyaz amp\u00fcllerin 16; floresanlar\u0131n da 70 kat\u0131.<\/p>\n

D\u00fcnya\u2019n\u0131n elektrik giderinin d\u00f6rtte birinin ayd\u0131nlatmaya ayr\u0131ld\u0131\u011f\u0131 d\u00fc\u015f\u00fcn\u00fcld\u00fc\u011f\u00fcnde, LED\u2019lerin sa\u011flayaca\u011f\u0131 tasarruf olduk\u00e7a \u00f6nemli boyutlardad\u0131r. Bunun yan\u0131nda elektrik \u015febekelerine eri\u015fimi olmayan 1,5 milyar insan, LED\u2019in yerel g\u00fcne\u015f panellerinden kar\u015f\u0131lanabilecek d\u00fc\u015f\u00fck enerji gereksinimi sayesinde ayd\u0131nlanma imk\u00e2n\u0131na sahip olabilecektir. 100 bin saatlik \u00f6m\u00fcrleriyle, \u00f6mr\u00fc 1000 saat olan akkor lamba ve 10 bin saat olan floresandan \u00e7ok daha tasarruflu olan LED lambalar, verim ve tasarruf parametreleri g\u00f6z \u00f6n\u00fcne al\u0131nd\u0131\u011f\u0131nda \u015fu anda gelece\u011fin ayd\u0131nlat\u0131c\u0131s\u0131 olarak g\u00f6r\u00fclmektedir.(7)<\/sup><\/p>\n

Nobel \u00d6d\u00fclleri\u2019nin insanl\u0131\u011fa b\u00fcy\u00fck katk\u0131 sa\u011flayan \u00e7al\u0131\u015fmalara verildi\u011fini tekrar vurgularsak, bu seneki Nobel Fizik \u00d6d\u00fcl\u00fc\u2019n\u00fcn mavi LED\u2019in mucitlerine verilmesi \u015fa\u015f\u0131rt\u0131c\u0131 de\u011fildir.<\/p>\n

Kaynaklar<\/strong><\/p>\n

1) http:\/\/www.nobelprize.org\/alfred_nobel\/<\/p>\n

2) http:\/\/www.radioaustralia.net.au\/international\/2014-10-08\/led-breakthrough-sees-japaneseborn-researchers-isamu-akasaki-hiroshi-amano-and-shuji-nakamura-awarde\/1376523<\/p>\n

3) http:\/\/ocw.tufts.edu\/Content\/36\/lecturenotes\/393138\/393210<\/p>\n

4) http:\/\/en.wikibooks.org\/wiki\/Semiconductor_Electronics\/Diode\/Construction_and_Operation<\/p>\n

5) \u201cThe Nobel Prize in Physics 2014 – Popular Information\u201d, \u00a0Nobelprize.org, <\/em>Nobel Media AB 2014. Web.<\/p>\n

6) http:\/\/blogs.thatpetplace.com\/thatfishblog\/wp-content\/Blue-LED.jpg<\/p>\n

7) \u201cThe 2014 Nobel Prize in Physics – Press Release\u201d, Nobelprize.org, <\/em>Nobel Media AB 2014. Web.<\/p>\n

Ekonomi, Bar\u0131\u015f ve Edebiyat Nobel \u00d6d\u00fclleri<\/strong><\/p>\n

2014 Nobel Ekonomi \u00d6d\u00fcl\u00fc<\/strong>, piyasa d\u00fczenlemeleri \u00fczerine \u00e7al\u0131\u015fmalar\u0131yla bilinen Frans\u0131z ekonomist Jean Tirole<\/strong>\u2019\u00fcn oldu. 61 ya\u015f\u0131ndaki Tirole\u2019\u00fcn \u015firket birle\u015fmeleri, karteller ve tekeller konusundaki \u00e7al\u0131\u015fmalar\u0131n\u0131n, devletlere az say\u0131da \u015firketin h\u00e2kimiyetindeki sekt\u00f6rleri nas\u0131l d\u00fczenleyece\u011fi konusunda yol g\u00f6sterdi\u011fi belirtiliyor. 2008 finans krizi sonras\u0131 \u00f6zellikle bankac\u0131l\u0131k d\u00fczenlemeleri t\u00fcm d\u00fcnyada b\u00fcy\u00fck \u00f6nem kazand\u0131. Dev firmalar\u0131 uysalla\u015ft\u0131rman\u0131n yolunu g\u00f6sterdi\u011fi dile getirilen Tirole, bir s\u00f6yle\u015fisinde, 2008 krizinin piyasa d\u00fczenlemelerinin \u00e7\u00f6kmesiyle \u00e7\u0131kt\u0131\u011f\u0131n\u0131 belirterek, \u201cPiyasan\u0131n verimlili\u011fine s\u0131n\u0131rs\u0131z g\u00fcven duyan ekonomistlerin vizyonu 30 y\u0131l geride kald\u0131\u201d diyordu.<\/p>\n

Nobel Bar\u0131\u015f \u00d6d\u00fcl\u00fc<\/strong>\u2019n\u00fcn bu y\u0131lki sahipleri \u00e7ocuk haklar\u0131 eylemcileri, Pakistanl\u0131 Malala Yusufzay<\/strong> ve Hintli Kayla\u015f Satyarti<\/strong> oldu. 17 ya\u015f\u0131ndaki Malala Yusufzay, Nobel tarihinde \u00f6d\u00fcle lay\u0131k g\u00f6r\u00fclen en gen\u00e7 isim. Yusufzay, Pakistan\u2019da k\u0131z \u00e7ocuklar\u0131n\u0131n e\u011fitim hakk\u0131n\u0131 savundu\u011fu i\u00e7in Taliban\u2019\u0131n hedefi haline gelmi\u015f, iki y\u0131l \u00f6nce okula giderken Taliban \u00fcyelerince ba\u015f\u0131ndan vurulmu\u015ftu. Sald\u0131r\u0131dan sa\u011f kurtulan Yusufzay, davas\u0131ndan vazge\u00e7medi ve konunun uluslararas\u0131 kamuoyunda yank\u0131 bulmas\u0131na katk\u0131 sa\u011flad\u0131. \u201cSesimi, seslerini duyuramayanlar i\u00e7in y\u00fckseltmeye \u00e7al\u0131\u015f\u0131yorum\u201d diyen Malala Yusufzay\u2019\u0131n kendi \u00fclkesinde daha \u00f6nce verdi\u011fi mesajlar \u015f\u00f6yle: \u201cSosyalizmin tek \u00e7\u00f6z\u00fcm oldu\u011fu kanaatindeyim ve t\u00fcm yolda\u015flar\u0131 bu m\u00fccadeleyi muzaffer bir sonuca \u00e7\u0131karmak i\u00e7in te\u015fvik ediyorum. Bizi gericilik ve s\u00f6m\u00fcr\u00fcn\u00fcn zincirlerinden yaln\u0131zca bu kurtaracakt\u0131r.\u201d<\/p>\n

Nobel Bar\u0131\u015f \u00d6d\u00fcl\u00fc<\/strong>\u2019ne lay\u0131k g\u00f6r\u00fclen di\u011fer isim olan 60 ya\u015f\u0131ndaki Satyarti ise Hintli \u00e7ocuk haklar\u0131 eylemcisi olarak tan\u0131n\u0131yor. \u00d6ne \u00e7\u0131kan eylemleri aras\u0131nda 1998\u2019de \u00e7ocuklar\u0131n i\u015fg\u00fcc\u00fc olarak kullan\u0131lmas\u0131na kar\u015f\u0131 y\u00fcr\u00fctt\u00fc\u011f\u00fc kampanya bulunuyor. 1990\u2019l\u0131 y\u0131llardan bu yana \u00e7ocuklar\u0131n i\u015fg\u00fcc\u00fcn\u00fcn s\u00f6m\u00fcr\u00fclmesine kar\u015f\u0131 m\u00fccadele eden Satrarti ve arkada\u015flar\u0131 sayesinde bug\u00fcne dek yakla\u015f\u0131k 80.000 \u00e7ocu\u011fun \u00e7e\u015fitli \u015fekillerde maruz kald\u0131klar\u0131 s\u00f6m\u00fcr\u00fcden kurtulup rehabilitasyon ve e\u011fitimlerinin sa\u011fland\u0131\u011f\u0131 biliniyor.<\/p>\n

Nobel Edebiyat \u00d6d\u00fcl\u00fc<\/strong>\u2019n\u00fcn ise, Frans\u0131z yazar Patrick Modiano<\/strong>\u2019ya \u201cKavranmas\u0131 en g\u00fc\u00e7 insan yazg\u0131lar\u0131n\u0131 anlatma ve Fransa\u2019n\u0131n i\u015fgal d\u00f6nemini g\u00f6zler \u00f6n\u00fcne serme konusunda bellek olgusunu sanat olarak kullanmas\u0131\u201dn\u0131 onurland\u0131rmak amac\u0131yla verildi\u011fi a\u00e7\u0131kland\u0131. \u0130sve\u00e7 Akademisi daimi sekreteri Peter Englund da Patrick Modiano\u2019yu \u201c\u00e7a\u011f\u0131m\u0131z\u0131n Marcel Proust\u2019u\u201d olarak niteledi.<\/p>\n

Kaynaklar<\/strong><\/p>\n

1) http:\/\/ilerihaber.org\/baris-odulu-sahibi-malala-bizi-gericilikten-ancak-sosyalizm-kurtarir\/3424\/<\/p>\n

2) http:\/\/haber.sol.org.tr\/dunyadan\/nobel-baris-odulu-malala-yusufzay-ve-kaylas-satyartiye-haberi-98438<\/p>\n

3) http:\/\/www.milliyet.com.tr\/devleri-uysallastirdi-nobel-i\/ekonomi\/detay\/1954103\/default.htm<\/p>\n

4) http:\/\/www.cumhuriyet.com.tr\/haber\/kitap\/132403\/2014_Nobel_Edebiyat_Odulu_sahibi_Patrick_Modiano_uzerine….html<\/p><\/blockquote>\n","protected":false},"excerpt":{"rendered":"

Yar\u0131 iletkenlerden \u00fcretilen parlak mavi \u0131\u015f\u0131k at\u0131mlar\u0131, ayd\u0131nlatma teknolojisinde temel bir d\u00f6n\u00fc\u015f\u00fcm\u00fcn \u00f6nc\u00fcs\u00fc oldu. 20. y\u00fczy\u0131l\u0131 ayd\u0131nlatan akkor lambalar\u0131n yerine, art\u0131k daha g\u00fc\u00e7l\u00fc ve daha tasarruflu alternatif ayd\u0131nlatma arac\u0131na, LED \u0131\u015f\u0131\u011fa sahibiz. Bilindi\u011fi gibi, Nobel \u00d6d\u00fclleri, Alfred Nobel\u2019in vasiyeti \u00fczerine \u201cinsanl\u0131\u011fa b\u00fcy\u00fck katk\u0131\u201d sa\u011flad\u0131\u011f\u0131 d\u00fc\u015f\u00fcn\u00fclen bilimcilere \u0130sve\u00e7 Kraliyet Bilim Akademisi taraf\u0131ndan 1901 y\u0131l\u0131ndan bu yana […]<\/p>\n","protected":false},"author":634,"featured_media":24839,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[166,26,22],"tags":[288,1085,3137,2015],"class_list":["post-24837","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-129-sayi","category-fizik","category-kimya","tag-fizik","tag-isik","tag-led-teknolojisi","tag-nobel-odulleri"],"acf":[],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t