探討以三五族半導體氮化鎵(Gallium Nitride ,GaN)取代被廣泛使用的電子傳輸及電洞阻擋層材料BCP(Bathocuproine)，以延長有機發光二極體(Organic Light Emitting Diode, OLED)使用時間。
本研究以自行組裝之射頻磁控濺鍍系統成長GaN薄膜，以液態鎵金屬(Gallium, Ga)做為靶材，以氬氣(Argon, Ar)及氮氣(Nitrogen, N2)為工作氣體，另外以連接ENI電源供應器之不銹鋼感應線圈，提供電漿氣體額外能量，探討不同氣體組成、基板溫度及ENI功率對GaN性質的影響。
依不同元件設計使用熱阻式蒸鍍系統蒸鍍有機層及金屬電極，首先選擇鋁金屬(Aluminium, Al)做為陰極傳遞電子給GaN，但發現鋁在成長GaN時因基板升至500℃會聚集而產生短路，因此使用氮化鈦(Titanium Nitride, TiN)取代鋁金屬解決聚集造成之短路。另外整面的GaN會有電子擴散情形，因此使用SiOx做為絕緣層定義電子可流通之位置，成功解決漏電問題。
實驗結果顯示，於10 mTorr鍍之TiN及GaN，其元件亮度僅119 cd/m2且驅動電壓(Turn on voltage)高達15 V，推測可能是GaN晶體結構有許多缺陷造成電流低，以及GaN沒有阻擋電洞跳躍至陰極的能力，使電洞與電子於GaN內無效複合。
為了解決上述兩問題，改變了射頻濺鍍參數及增加步驟。將鍍膜時的工作壓力降到5 mTorr，可得品質較佳的TiN及GaN薄膜，其中GaN的XRD強度從小於1000 cps提升至15000 cps。接續增加氮電漿表面處理以降低GaN表面缺氮造成的缺陷，而實驗結果成功將亮度從原本的119 cd/m2提升至1091cd/m2。

This article is about the research of Gallium Nitride(GaN) as electron injection and hole blocking layer in Organic Light Emitting Diode(OLED). The traditional material for electron injection and hole blocking layer is BCP, which Tg point is low. We want to use GaN to replace Bathocuproine(BCP) to enhance the stability of OLED device. Using RF sputtering method to grow GaN film under different condition, thermal evaporation system to deposit organic layer. In the begin the device performance was bad ,with turn on voltage up to 15V and only 119cd/m2. After figuring out the problem, change the working pressure from 10mTorr to 5mTorr, and treat the surface with N2 plasma. The device performance now enhances from 119cd/m2 to 1091cd/m2.

1. http://www.mem.com.tw/article_content.asp?sn=1209260005.
2. http://www.digitimes.com.tw.
3. km.twenergy.org.tw/ReadFile/?p=KLBase&n=2014121142744.pdf.
4. Mori, T. and Y. Masumoto, Effect of Organic Alloy for Suppression of Polycrystallization in BCP Thin Film. Journal of Photopolymer Science and Technology, 2006. 19(2): p. 209-214.
5. 陳建人, 真空技術與應用. 2004: 行政院國家科學委員會精密儀器發展中心.
6. Zhang, C.G., et al., Effect of growth conditions on the GaN thin film by sputtering deposition. Journal of Crystal Growth, 2007. 299(2): p. 268-271.
7. Shinoda, H. and N. Mutsukura, Structural properties of GaN and related alloys grown by radio-frequency magnetron sputter epitaxy. Thin Solid Films, 2008. 516(10): p. 2837-2842.
8. Daigo, Y. and N. Mutsukura, Synthesis of epitaxial GaN single-crystalline film by ultra high vacuum r.f. magnetron sputtering method. Thin Solid Films, 2005. 483(1-2): p. 38-43.
9. Ross, J. and M. Rubin, High-quality GaN grown by reactive sputtering. Materials Letters, 1991. 12(4): p. 215-218.
10. Kim, J.H. and P.H. Holloway, Wurtzite to zinc-blende phase transition in gallium nitride thin films. Applied Physics Letters, 2004. 84(5): p. 711.
11. Junaid, M., et al., Electronic-grade GaN(0001)/Al[sub 2]O[sub 3](0001) grown by reactive DC-magnetron sputter epitaxy using a liquid Ga target. Applied Physics Letters, 2011. 98(14): p. 141915.
12. 詹逸民, 高效能有機發光元件製作技術之研究. 2004, 國立成功大學化學工程學系研究所博士班論文.
13. 周永晟, 具有載子注入平衡共主體結構之黃光有機發光二極體. 2012, 國立清華大學材料科學工程研究所碩士論文.
14. S. Miyata., Organic Electroluminescence Materials and Devices. 1997: Golden and Breach Science Publishers,Netherlands.
15. Mu, H., Carriers Injection and Transport in Small Molecule Organic Light Emitting Diodes(OLED). 2006, Division of Research and Advanced Studies of the University of Cincinnati.
16. Baldo, M.A., et al., Highly efficient phosphorescent emission from organic electroluminescent devices. Nature, 1998. 395(6698): p. 151-154.
17. Zhou, J., et al., Roughening the white OLED substrate's surface through sandblasting to improve the external quantum efficiency. Organic Electronics: physics, materials, applications, 2011. 12(4): p. 648-653.
18. Kwon, H., et al. Microlens array film with full fill factor for enhancing outcoupling efficiency from OLED lighting. in 4th International Conference on Solid-State Sensors, Actuators and Microsystems, TRANSDUCERS and EUROSENSORS '07, June 10, 2007 - June 14, 2007. 2007. Lyon, France: Inst. of Elec. and Elec. Eng. Computer Society.
19. Tanaka, S., Y. Kawakami, and Y. Naito. Improvement of the external extraction efficiency of OLED by using a pyramid array. in Organic Light-Emitting Materials and Devices VIII, August 2, 2004 - August 4, 2004. 2004. Denver, CO, United states: SPIE.
20. Acharya, R. and X.A. Cao, High-brightness organic light-emitting diodes based on a simplified hybrid structure. Applied Physics Letters, 2012. 101(5): p. 053306.
21. Bolink, H.J., et al., Inverted Solution Processable OLEDs Using a Metal Oxide as an Electron Injection Contact. Advanced Functional Materials, 2008. 18(1): p. 145-150.
22. Tokmoldin, N., et al., A Hybrid Inorganic-Organic Semiconductor Light-Emitting Diode Using ZrO2as an Electron-Injection Layer. Advanced Materials, 2009. 21(34): p. 3475-3478.
23. Zhong, A. and K. Hane, Growth of GaN nanowall network on Si (111) substrate by molecular beam epitaxy. Nanoscale Research Letters, 2012. 7(1): p. 1-7.
24. Chuah, L.S., Z. Hassan, and H.A. Hassan, High-quality In0.47Ga0.53N/GaN heterostructure on Si(111) and its application to MSM detector. Microelectronics International, 2008. 25(2): p. 3-8.
25. Junaid, M., et al., Two-domain formation during the epitaxial growth of GaN (0001) on c-plane Al2O3 (0001) by high power impulse magnetron sputtering. Journal of Applied Physics, 2011. 110(12): p. -.
26. Saoula, N., K. Henda, and R. Kesri, Deposition of Titanium Nitride Thin Films onto Silicon by RF Reactive Magnetron Sputtering. Materials Science Forum, 2009. 609: p. 117-121.
27. Liu, Y., et al., Nitrogen Gas Flow Ratio and Rapid Thermal Annealing Temperature Dependences of Sputtered Titanium Nitride Gate Work Function and Their Effect on Device Characteristics. Japanese Journal of Applied Physics, 2008. 47(4): p. 2433-2437.
28. Wakabayashi, H., et al. Novel W/TiNx metal gate CMOS technology using nitrogen-concentration-controlled TiNx film. in 1999 IEEE International Devices Meeting (IEDM), December 5, 1999 - December 8, 1999. 1999. Washington, DC, USA: IEEE.
29. Jiang, N., et al., XPS study for reactively sputtered titanium nitride thin films deposited under different substrate bias. Physica B: Condensed Matter, 2004. 352(1-4): p. 118-126.
30. Dimitriadis, C.A., et al., Contacts of titanium nitride to n- and p-type gallium nitride films. Solid-State Electronics, 1999. 43(10): p. 1969-1972.
31. Weingarten, M., et al. Characterization of charge carrier injection in organic and hybrid organic/inorganic semiconductor devices by capacitance-voltage measurements. in Organic Light Emitting Materials and Devices XVI, August 12, 2012 - August 15, 2012. 2012. San Diego, CA, United states: SPIE.
32. Saarinen, K., et al. Vacancies as compensating centers in bulk GaN: Doping effects. in BNS 2002, May 18, 2002 - May 23, 2002. 2002. Amazonas, Brazil: Elsevier.
33. Ganchenkova, M. and R. Nieminen, Nitrogen Vacancies as Major Point Defects in Gallium Nitride. Physical Review Letters, 2006. 96(19).
34. Van de Walle, C.G. and J. Neugebauer, First-principles calculations for defects and impurities: Applications to III-nitrides. Journal of Applied Physics, 2004. 95(8): p. 3851-3879.
35. Bai, Y., et al., White organic light-emitting devices with high color purity and stability. Semiconductor Science and Technology, 2014. 29(4).
36. Reshchikov, M.A. and H. Morkoç, Luminescence properties of defects in GaN. Journal of Applied Physics, 2005. 97(6): p. 061301.
37. Demchenko, D., I. Diallo, and M. Reshchikov, Yellow Luminescence of Gallium Nitride Generated by Carbon Defect Complexes. Physical Review Letters, 2013. 110(8).