| 摘要(英) |
Aluminum gallium nitride (AlGaN) is the most commonly used material for deep ultraviolet light emitting-diodes (DUV LEDs, emission wavelength < 290 nm). However, the external quantum efficiencies (EQEs) of DUV LEDs rarely reach 10 %, despite years of research efforts. The main reason is the extremely high activation energies of conventional acceptors in p-type AlxGa1-xN (170 – 510 meV). This intrinsic drawback subsequently results in low hole injection efficiency, and accordingly the conductivity of p-AlxGa1-xN. To overcome the difficulty, we employ boron nitride (BN) as the alternative to p-type AlGaN. BN is reported to exhibit much lower acceptor activation energy than AlGaN, in addition to her high chemical and thermal stability. These are attractive merits for the applications in DUV LEDs. To evaluate the electrical properties of p-type BN (p-BN), we systematically characterized p-BN with Hall measurements using different metal electrodes, annealing conditions, growth pressure, and V/III ratios with the intention to achieve ohmic contact on the two-dimensional layer. It is found that adding a 3-nm InGaN contact layer on the surface, or reducing the V/III ratio, can effectively reduce the contact resistance of p-BN. |
| 參考文獻 |
[1] The electromagnetic spectrum , Available at: https://xpfamilysupport.org/learn/what-is-uv/
[2]Application of UVA,UVB,UVC, Available at:
https://www.green-sources.com/uvc.html
[3] M. Kneissl, J. Rass, A brief review of III – Nitrides UV emitter Technologies and their applications, III – Nitride Ultraviolet Emitters. Springer series in Materials Science 227, Springer International Publishing, Switzerland (2016).
[4] H. X. Jiang, and J. Y. Lin, Hexagonal boron nitride for deep ultraviolet photonic devices. Semicond. Sci. Technol. 29, 084003 (2014).
[5] M. Soltani, R. Soref, T. Palacios, and D. Englund, AlGaN/AlN integrated photonics platform for the ultraviolet and visible spectral range. Optics Express 24, 25415 (2016).
[6] M.Noritoshi and H.Hideki, Realization of high efficiency deep UV LEDs using transparent p-AlGaN contact layer. Phys. Status Solidi C 10, 1521 (2013).
[7]TLM measurement, Available at: https://www.ir.nctu.edu.tw/bitstream/11536/51935/9/151609.pdf
[8]Hall measurement, Available at: http://ezphysics.nchu.edu.tw/prophys/basicexp/expnote/hall/hall_920703.pdf
[9] 劉文獻, 提升p 型Al0.5Ga0.5N歐姆接觸電極的導電性及反射率.
國立中央大學. 碩士論文 (2018)
[10] D. J. Kim, D. Y. Ryu, N. A. Bojarczuk, J. Karasinski, S. Guha, S. H. Lee, and J. H. Lee, Thermal activation energies of Mg in GaN:Mg measured by the Hall effect and admittance spectroscopy. J. Appl. Phys. 88, 2564 (2000).
[11] Jin-Kuo Ho, Low-resistance ohmic contacts to p-type GaN achieved by the oxidation of Ni/Au films. Appl. J. Appl. Phys. 86, 4491 (1999).
[12] Li-Chien Chen, Microstructural investigation of oxidized Ni/Au ohmic contact to p-type GaN. Appl. J. Appl. Phys. 86, 3826 (1999).
[13] Li Xiao-Jing, Zhao De-Gang, He Xiao-Guang, and Wu Liang Liang, Influence of different annealing temperature and atmosphere on the Ni/Au Ohmic contact to p-GaN. Acta Phys. Sin. 62 (2013).
[14] D. Mistele, Investigation of Ni/Au-contacts on p-GaN annealed in different atmospheres. J. Cryst. Growth 230, 564 (2001).
[15] Ho Won Jang, Soo Young Kim and Jong-Lam Lee, Mechanism for Ohmic contact formation of oxidized Ni/Au on p-type GaN. J. Appl. Phys. 94, 1748 (2003).
[16] S. Nikishin, Mechanism of carrier injection in (Ni/Au)/p-AlxGa1-xN:Mg (0≤x≤0.1) Ohmic contacts. Appl. Physics Letters. 95, 163502 (2009).
[17] Jin-Kuo Ho, Low-resistance ohmic contacts to p-type GaN achieved by the oxidation of Ni/Au films. J. Appl. Phys. 86, 4491 (1999).
[18] Han-Ki Kim, Tae-Yeon Seong, Ilesanmi Adesida, Chak Wah Tang, and Kei May Lau, Low-resistance Pt/Pd/Au ohmic contacts to p-type AlGaN. Appl. Phys. Letters 84, 1710 (2004).
[19] HL5500PC Hall effect Measurement System – Opearating Manual, Accent.
[20] Dong-Joon Kim, Effect of Growth pressure on Indium Incorporation During the Growth of InGaN by MOCVD. JEM. 30, 99 (2001).
[21] Qing S. Paduano , Michael Snure and Jodie Shoaf , Effect of V/III ratio on the growth of hexagonal boron nitride by MOCVD. Mater. Res. Soc. Symp. Proc. 1726 (2015).
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