利用自旋發光二極體探討自旋電子經鐵三矽至砷化鎵注入之極化率研究

簡易檢索 / 詳目顯示

回結果列表

研究生：	李奕昇 Li, Yi-Sheng
論文名稱：	利用自旋發光二極體探討自旋電子經鐵三矽至砷化鎵注入之極化率研究 Study of Spin Injection from Fe3Si into GaAs by Spin Light-Emitting-Diode
指導教授：	郭瑞年 Kwo, Raynien 洪銘輝 Hong, Minghwei
口試委員:
學位類別：	碩士 Master
系所名稱：	理學院 - 物理學系 Department of Physics
論文出版年：	2009
畢業學年度：	97
語文別：	英文
論文頁數：	72
中文關鍵詞：	自旋電子學、電子自旋發光二極體、鐵三矽、自旋注入、自旋極化率、半金屬、分子束磊晶
外文關鍵詞：	Spintronics, Spin-LED, Fe3Si, Spin Injection, Spin Polarization, Half metal, Molecular Beam Epitaxy
相關次數：	點閱：2 下載：0
分享至:	分享至facebook 分享至twitter

查詢本校圖書館目錄查詢臺灣博碩士論文知識加值系統勘誤回報

電子自旋發光二極體是在精確量測電子自旋極化率上一種非常有力的方法。基本原理是透過偵測發光二極體光之圓比率反推回電子自旋極化率。然而，在維持自旋電子極化率是困難的，原因是自旋電子流自鐵磁性材料注入半導體的過程中，極化率勢必受到影響。在二極體之量子井中，極化自旋電子將會與非極化之電洞結合，產生具有圓偏振極化率之光。在這個研究中，我們將著重在具有鐵三矽與砷化鎵異質結構之自旋發光二極體，希望能偵測出鐵三矽之電子自旋極化率。鐵三矽被視為是一種在費米能階上百分之百極化方向之半金屬材料，使鐵三矽可成為高電子極化率注入性材料。在製程上，電子自旋發光二極體是由分子束磊晶技術所成長，量測上是利用低溫磁性光學量測系統，利用低溫高磁場環境來量測光的圓極化率。然而，在數據上已經量測到圓極化率，也證實光的圓極化率是來自於鐵三矽。未來，希望能藉由改變二極體結構以提高光之圓極化率，以確實偵測到鐵三矽之極化率。

The spin-polarized light-emitting diode (spin-LED) is a very powerful means for accurately quantifying spin injection through detecting left and right circular polarized light. It is difficult to maintain the spin polarization injected from a ferromagnetic metal into a semiconductor. The spin polarized electron would combine with un-polarized hole and generate circular polarized light at quantum well. In this work, we have investigated the spin-LEDs made of Fe3Si/GaAs heterostructures. Fe3Si, as a Heusler alloy, is expected to be half metal with 100% spin polarization at the Fermi level, thus making Fe3Si an attractive material for spin injection. The spin-LED was deposited by in-situ multi-chamber MBE system. Furthermore, we have detected the circular polarization by a home-built low temperature measurement system which we set up. In the future, we plan to measure the higher and closer the spin polarization which was generated from Fe3Si.

CHAPTER 1 INTRODUCTION ........................................................................ 1
1 Background ................................................................................................................. 1
2 Spin-FET ...................................................................................................................... 3
CHAPTER 2 THEORY ....................................................................................... 5
1 Light Emitting Diode .................................................................................................... 5
2 Spin Light-Emitting Diodes ........................................................................................ 11
3 Spin Injection ............................................................................................................ 13
4 Half Metal ................................................................................................................. 16
5 Heusler alloy and Fe3Si Structure ............................................................................... 17
6 Spin Detection ........................................................................................................... 19
7 Polarized Light Theory ............................................................................................... 25
CHAPTER 3 INSTRUMENTS ....................................................................... 28
IV
1 Molecular Beam Epitaxy ............................................................................................ 28
2 Liquid Crystal Variable Retarder ................................................................................ 30
3 Measurement system ................................................................................................ 32
4 LabVIEW .................................................................................................................... 37
CHAPTER 4 HETEROSTRUCTURE DESIGN AND FABRICATION...... 38
1 Heterostructure design .............................................................................................. 38
2 Epitaxy ...................................................................................................................... 41
3 Fabrication ................................................................................................................ 44
CHAPTER 5 MEASURING RESULTS AND DISCUSSIONS ..................... 52
1 Brightness and simulated results of Spin-LEDs .......................................................... 52
2 The optical spectrum analysis ................................................................................... 56
3 The original methods for measuring circular polarization and results ....................... 60
4 The optical phase varied methods for measuring circular polarization and results .... 63
CHAPTER 6 CONCLUSION ........................................................................... 70
CHAPTER 7 REFERENCE ............................................................................. 71

                                

[1] S. Datta, and B. Das, Applied Physics Letters 56, 665 (1990).
[2] E. F. Schubert, Light-emitting diodes (Cambridge University Press, Cambridge ; New York, 2006), pp. x.
[3] G. Schmidt et al., Physical Review B 62, R4790 (2000).
[4] E. I. Rashba, Physical Review B 62, R16267 (2000).
[5] A. Fert, and H. Jaffres, Physical Review B 6418 (2001).
[6] S. H. Liou et al., Journal of Applied Physics 73, 6766 (1993).
[7] M. Hong et al., (Elsevier Science Bv, 1991), pp. 984.
[8] S. H. Liou et al., 1993), pp. 6766.
[9] D. Y. Noh et al., Applied Physics Letters 68, 1528 (1996).
[10] J. Herfort, H. P. Schonherr, and K. H. Ploog, Applied Physics Letters 83, 3912 (2003).
[11] A. Ionescu et al., Physical Review B 71, 9 (2005).
[12] H. D. Cheong et al., Journal of the Korean Physical Society 39, 568 (2001).
[13] Zakharchen, and F. Meier, Optical orientation (North-Holland ;
Sole distributors for the U.S.A. and Canada, Elsevier Science Pub. Co., Amsterdam ; New York
New York, 1984), pp. xi.
[14] G. R. Fowles, Introduction to modern optics (Dover Publications, New York, 1989), pp. viii.
[15] A. T. Hanbicki et al., Applied Physics Letters 80, 1240 (2002).
[16] A. T. Hanbicki et al., Applied Physics Letters 82, 4092 (2003).
[17] R. I. Dzhioev et al., Physical Review B 66, 7 (2002).
[18] Y. L. Hsu et al., Journal of Crystal Growth 301, 588 (2007).
72
[19] B. T. Jonker et al., Applied Physics Letters 79, 3098 (2001).
[20] R. Mallory et al., Physical Review B 73 (2006).
[21] G. Kioseoglou et al., Applied Physics Letters 87 (2005).
[22] O. M. J. van 't Erve et al., Applied Physics Letters 84, 4334 (2004).
[23] A. Kawaharazuka et al., Applied Physics Letters 85, 3492 (2004).

全文公開日期本全文未授權公開 (校內網路)
全文公開日期本全文未授權公開 (校外網路)

簡易檢索 / 詳目顯示

相關論文