İLETİŞİM:
 
Bilkent Üniversitesi
 
Ulusal Nanoteknoloji Arastirma Merkezi (UNAM)
 
Malzeme Bilimleri ve Nanoteknoloji Enstitüsü
 
Ankara - TURKIYE
 
Phone:
+90 (312) 290 2107
 
Fax:
+90 (312) 266 4579
 
e-posta: imer@bilkent.edu.tr

 

Yard. Doç. Dr. Bilge İmer
 
 

EĞİTİM

University of California Santa Barbara (UCSB)

Tez: “Improved quality non-polar III-Nitride films and devices” (PDF)

        “Geliştirilmiş kalitede nonpolar III-nitrür filimler ve cihazlar”

Committee: Steve DenBaars, James Speck, Shuji Nakamura, Evelyn Hu, Chris Van de Walle

       İş yönetimi üzerine Ekonomi mastırı
        Teknoloji Yönetimi Sertifikası “Şirketler ve girişimcilik bağlamında yeni ürün geliştirme ve yeni iş açma” üzerine.

University of Pittsburgh

        Ortadoğu Teknik Üniversitesi (ODTÜ), Metalurji ve Malzeme Bilimi Mühendisliği bölümünden transfer oldu

ARAŞTIRMA

· MOCVD (Metalorganic Chemical Vapor Deposition) ile ince filim ve kristal büyütme

· Mikrofabrikasyon ve Cihaz İşleme: Nitrür bazlı cihazların işlenmesi:  photolithography, reactive ion etching (RIE), inductively coupled plasma etching (ICP), thin film deposition (PECVD, e-beam), RTA

· Karakterizasyon: Hall & TLM, PL, EL,  I-V, AFM, X-RAY Diffraction, SEM Measurement Techniques and Analysis, Q - dielectric factor measurements - Single Port Reflection Method with Network Analyzer

 

UCSB’de çalıştığı sürece Mitsubishi Chemical, SSLDC (Solid State Lighting and Display Center) ve JST-ERATO (Japan Science and Technology) projelerinde çalıştı ve finanse edildi.

· Amerikan Enerji Bakanlığı’nın 2020 yılına kadar 98 milyar dolarlık enerji tasarrufu sağlanması projesi kapsamında polarizasondan arınmış (non-polar) yarı-iletken III-Nitrürlerin malzeme özellikleri, kristal kalitesi geliştirilmesi ve cihaz performanslarının verimliliğinin arttırılması konusunda çalıştı. Bu uğurda;

· “Sidewall Lateral Epitaxial Overgrowth (SLEO)” ismini verdiği, kristal içerisindeki deformasyon ve dislokasyonların yoğunluklarını 103-104 kez indirgeyen yeni bir fabrikasyon ve büyütme tekniği geliştirdi.  Bu yeni teknik ile rapor edilmiş en düşük dislokasyon ve deformasyon yoğunluğunu düşük maliyet ve zahmetle elde etti ve uluslararası bir patent aldı.

·  m-yüzeyi denilen, (1-100) oriyentasyonlu kristal yüzeyi üzerinde MOCVD (Metalorganic Chemical Vapor Deposition) yöntemini kullanarak Dünya’da ilk kez cihaz yapma kalitesinde Nitrür bazlı malzemeler büyüttü.  Ve bu konuda uluslararası bir patent aldı.

· 360 nm UV dalga boyunda çalışan, GaN/AlGaN kuantum kuyucuklu aktif bölgeden oluşmuş, yüksek elektron hareketliliği ve rekor dahili kuantum verimliliği (internal quantum efficiency) olan a-yüzeyi üzerine büyütülmüş LED’ler yaptı.

· AlGaN/GaN kuantum kuyucuklarından oluşmuş LED yapılarının büyütülmesi, yapısal, elektriksel ve optik karaketizasyonu konusunda Amerikan Ordu Laboratuvarları (Army Research Labs) ile bir araştırma yürüttü.

PATENTLER

· U.S. patent # 20060270076

”Defect Reduction of Non-polar {11-20} a- and {1-100} m-plane GaN with Single-Step Sidewall Lateral Epitaxial Overgrowth (SLEO)”, Bilge Imer, James S. Speck, Steven P. DenBaars, submitted on March 30,2005 – granted on November 30, 2006.

· U.S. patent # 20060270087

 “Growth of non-polar (1-100) m-plane GaN with Metalorganic Chemical Vapor Deposition (MOCVD)”, Bilge Imer, James S. Speck, Steven P. DenBaars, submitted on March 30,2005 – granted on November 30, 2006.

YAYINLAR

A. HAKEMLİ YAYINLAR

I.     YAYINLANANLAR  (Agustos 2007 itibariyle toplam kaynak gösterilme 56)

1-”Structural and electrical characterization of a-plane GaN grown on a-plane SiC”, M. D. Craven, A. Chakraborty, B. Imer, F. Wu, S. Keller, U. K. Mishra, J. S. Speck, and S. P. DenBaars, Phys. Stat. Sol. (c) 0, No. 7, 2132-2135, October 2003

2- Microstructural evolution of a-plane GaN grown on a-plane SiC by Metalorganic chemical vapor deposition”, M. D. Craven, F. Wu, A. Chakraborty, B. Imer, U. K. Mishra, S. P. DenBaars, and J. S. Speck, Applied Physics Letters, Vol. 84, No.8, February 2004

3- ”Growth of thick (11-20) GaN using a metal interlayer”, P. R. Tavernier, B. Imer, S. P. DenBaars, and D. R. Clarke, Applied Physics Letters, Vol. 85, No. 20, November   2004

4- “Intensity Dependent Time-Resolved Photoluminescence Studies of GaN/AlGaN Multiple Quantum Wells of Varying Well Width on Laterally Overgrown a‑plane and Planar c-plane GaN “,(G. A. Garrett, H. Shen, W. Wraback) from U.S. Army Research Laboratory, Sensors and Electron Devices Directorate (B. Imer, B. Haskell, S. Keller, S. Nakamura, S. P.  DenBaars) from UCSB,  Physica Status Solidi (a), No. 5, 846 (2005)

5- “Polarized photoreflectance spectroscopy of strained A-plane GaN films on R-plane sapphire”, (Sandip Ghosh, Pranob Misra, and Holger T. Grahn) from Paul-Drude-Institut fur Festk¨orperelektronik, Berlin, Germany (Bilge Imer, Shuji Nakamura, S. P. DenBaars and J. S. Speck) from UCSB, J. of Appl. Phys.,98, 026105, July 2005

6- “High Quality Non-polar ( a-plane GaN with Sidewall Lateral Epitaxial Overgrowth (SLEO)”, Bilge Imer, James S. Speck, Steven P. DenBaars,  Applied Physics Letters, Vol. 88, Number 6-061908, February 2006

7- “Temperature-dependent radiative lifetimes of excitons in non-polar GaN/AlGaN quantum wells”, (S. Rudin, G. A. Garrett, H. Shen, M. Wraback) from U.S. Army Research Laboratort, Sensors and Electronic Devices Directorate ( B. Imer, B. Haskell, J. S. Speck, S. Keller, S. Nakamura, and S. P. DenBaars) from UCSB,  IEEE International Semiconductor Device Research Symposium, 2005 International Proceedings, Dec 7-9, 2005, pp. 225 -226

8- “Polarization anisotropy in GaN films for different nonpolar orientations studied by polarized photoreflectance spectroscopy”,(Pranob Misra, Udo Behn, Oliver Brandt and Holger T. Grahn) from Paul-Drude-Institut fur Festk¨orperelektronik, Berlin, Germany(Bilge Imer, Shuji Nakamura, S. P. DenBaars and J. S. Speck) from UCSB, Applied Physics Letters. Vol.88,Number 161920, April 2006 

9- “Optical polarization anisotropy in strained a-plane GaN films on r-plane sapphire”, (Sandip Ghosh, Pranob Misra, and Holger T. Grahn) from Paul-Drude-Institut fur Festk¨orperelektronik, Berlin, Germany (Bilge Imer, Shuji Nakamura, S. P. DenBaars and J. S. Speck) from UCSB, Physica Status Solidi (b). Vol.243,Number 7, pp. 1441 – 1445, June 2006

10- “Stability of ( m-plane GaN films grown by metalorganic chemical vapor deposition (MOCVD)”, Bilge Imer, Feng Wu, Michael D. Craven, James S. Speck and Steven P. DenBaars, Japanese Journal of Applied Physics, Vol. 45, No. 11, 8644, November 2006 

11- “Growth evolution in Sidewall Lateral Epitaxial Overgrowth (SLEO)”, Bilge Imer, Feng Wu, James S. Speck, Steven P. DenBaars, Journal of Crystal Growth, Vol. 306, 330-338, August 2007

 

II.      YAYIN AŞAMASINDA OLANLAR

12- “Improved efficiency nonpolar a-plane GaN/AlGaN UV LEDs”, Bilge Imer, Matt Schmidt, Ben Haskell, Barry Zhong, Kwang-choong Kim, Feng Wu, Tom Mates, Stacia Keller, Shuji Nakamura, James S. Speck, and Steven P. DenBaars (In review at Physica Status Solidi –a)

13- “Electrical Characterization of low defect density nonpolar a-plane GaN grown with sidewall lateral epitaxial overgrowth (SLEO)”, Bilge Imer, Ben Haskell, Siddharth Rajan, Umesh K. Mishra, Shuji Nakamura, James S. Speck, and Steven P. DenBaars (In review at Applied Physics Letters)

 

B.   KONFERANSLAR VE HAKEMSİZ YAYINLAR

1-  “The 2000 Senior Technical Symposium” April 11, 2000 University of Pittsburgh, Pittsburgh, PA

 “Low Temperature Processing of High Q Dielectric Resonator Ceramics for Microwave Dielectric Resonator Applications”, B. Imer, I. Nettleship, P. P.  Phule

2- 102nd Annual Meeting & Exposition of American Ceramic Society, May 1, 2000,  St. Louis, MO

  “Microstructure Evolution in BZT Ceramics Processed at Low Temperature”,  S.H. Ra, B. Imer, I. Nettleship, P.P. Phule

3- 2nd Annual Review of Solid State Lightning an Display Center (SSLDC)  in Fall 2003, Santa Barbara

 “Structural and Electrical Characterization of non-polar a-plane GaN grown via  MOCVD” B. Imer, M. D. Craven, S. Keller, U. K. Mishra, S. P. DenBaars

4-  IWNS July 21, 2004, Pittsburgh, PA:

 “Time-Resolved Photoluminescence Studies of LEO a-GaN and Planar c-GaN MQW of Varying Well and Barrier Thickness”, (G. A. Garrett, A. V. Samapth, J. Collins, M. Wraback) from U.S. Army Research Laboratory, Sensors and Electron Devices Directory (B. Imer, B. Haskell, S. Keller, S. Nakamura, S. P. DenBaars) from UCSB 

5-  “Nitride Seminars” series for Interdisciplinary Center for Wide Bandgap Semiconductors and The Solid State Lighting & Display Center, UCSB, Santa Barbara, CA, March 3, 2005

“A New Approach to Defect Reduction in Non-polar ( a-GaN”, Bilge Imer, Feng Wu, James S. Speck, Steven P. DenBaars 

6- 47th Electronic Materials Conference (EMC), Santa Barbara,  CA, June 22-24, 2005

“Growth of Planar, Non-polar (1 -1 0 0) m-plane GaN over m-plane SiC by Metalorganic Chemical Vapor Deposition (MOCVD)”, Bilge Imer, Feng Wu, James S. Speck, Steven P. DenBaars

7- 6th International Conference on Nitride Semiconductors (ICNS), Bremen, Germany, August, 29- September, 2, 2005

  “A New Approach to Defect Reduction in Non-polar ( a-GaN: Sidewall Lateral Epitaxial Overgrowth (SLEO)”, Bilge Imer, Feng Wu, James S. Speck, Steven P.   DenBaars

8- 6th International Conference on Nitride Semiconductors (ICNS), Bremen, Germany, August, 29- September, 2, 2005

“Optical Polarization Anisotropy in Strained A-Plane GaN Films on R-Plane Sapphire”,  S. Gosh, P. Misra, H.T. Grahn, Bilge Imer, S. Nakamura, S. P. DenBaars J. S. Speck

9- 4th  Annual Review of Solid State Lightning an Display Center(SSLDC)  in Fall 2005, Santa Barbara

“Sidewall Lateral Epitaxial Overgrowth (SLEO)”, B. Imer, Feng Wu, James S. Speck, Steven P. DenBaars

10- IEEE International Semiconductor Device Research Symposium, Dec. 7-9, 2005, Bethesda, Maryland

“Temperature-depedent Radiative Lifetime of Excitons in Non-polar GaN/AlGaN Quantum Wells”, (S. Rudin, G. A. Garrett, H. Shen, and M. Wraback) from Army Research Labs (B. Imer, B. Haskell, J. S. Speck, S. Keller, S. Nakamura, and S. P. DenBaars) from UCSB

11- The International Symposium on Blue Laser and Light Emitting Diodes (ISBLLED) 2006, Montpellier, France, May 2006

“Polarization Anisotropy in Nonpolar GaN films studied by polarized photoreflectance spectroscopy”,  Udo Behn, Pranob Misra, Holger Grahn, Bilge Imer, Shuji Nakamura, Steven DenBaars and James Speck

12- 28th International Conference on the Physics of Semiconductors (ICPS), July 2006, Vienna, Austria,

“Temperature-dependent Radiative Lifetime of Excitons in Non-polar GaN/AlGaN Quantum Wells”, S. Rudin, G. A. Garret, H. Shen, and M. Wraback (from U.S. Army Research Laboratory, Sensors and Electron Devices Directory) B. Imer, B. Haskell, J. S. Speck, S. Keller, S. Nakamura, and Steven P. DenBaars (from UCSB)