Optical Properties of Li:ZnO Thin Films with [101] Orientation

doi:10.3724/SP.J.1077.2007.00359

Abstract

Abstract: [101] oriented Li:ZnO thin films were prepared on limeglass substrates by using a r.f. magnetron sputtering method. The effect of annealing temperature on the optical properties of Li:ZnO thin films was investigated. Comparing with [002] oriented Li:ZnO film, the as-deposited [101] oriented film has wide band gap (E_g), though it red-shifts from 3.37 to 3.29 eV after annealing at 560-580℃, companying with the shrinkage of unit cell. When the [101] oriented Li:ZnO film is annealed at high temperature (610℃), its band gap shifts back to 3.35eV. The photoluminescence (PL) studies confirm that there exhibit 399nm, 421nm and 468nm PL peaks for all the films. However, when the films are annealed at 560--580℃, the near-band-edge (NBE) emission peak at 380nm of the samples disappears and the band-to-band UV emission near 360nm slightly shifts to large wavelength due to the decrease of E_g. It is considered that the PL peak of 399nm is induced by Li dopant and the other peaks are arisen from the intrinsic defects in ZnO lattice structure. The effects of Li dopant on the structural and optical characteristics were also iscussed.

Key words: ZnO thin film, Li dopant, [101] orientation, photoluminescence

CLC Number:

O484

ZHU Xing-Wen,LI Yong-Qiang,LU Ye,LI Ying-Wei,XIA Yi-Ben. Optical Properties of Li:ZnO Thin Films with [101] Orientation[J]. Journal of Inorganic Materials, DOI: 10.3724/SP.J.1077.2007.00359.

References

[1] Yu P, Tang Z K, Wong G K L, et al. In: Conference on Quantum Electronics and Laser Science (QELS)-Technical Digest Series, 1996, 9: 102--103.
[2] Bagnall D M, Chen Y F, Zhu Z, et al. Appl. Phys. Lett., 1997, 70 (17): 2230--2232.
[3] Cao H, Zhao Y G, Ong H C, et al. Appl. Phys. Lett., 1998, 73 (25): 3656--3658.
[4] Zu P, Tang Z K, Kawasaki M, et al. Solid State Communications, 1997, 103 (8): 459--463.
[5] Chen Y F, Bagnall D M, Koh H J, et al. J. Appl. Phys., 1998, 84 (7): 3912--3918.
[6] Lin B X, Fu Z X, Jia Y B. Appl. Phys. Lett., 2001, 79 (7): 943--945.
[7] Wang Q P, Zhang D H, Xue Z Y, et al. Applied Surface Science, 2002, 201 (1-4): 123--128.
[8] Li H Q, Ning Z Y, Cheng S H, et al. Acta Physica Sinica, 2004, 53 (3): 867--870.
[9] Wang Q P, Zhang D H, Xue Z Y, et al. Optical Materials, 2004, 26 (1): 23--26.
[10] Fan D H, Ning Z Y, Jiang M F. Applied Surface Science, 2005, 245 (1-4): 414--419.
[11] Shan F K, Kim B I, Liu Z F, et al. J. Applied Physics, 2004, 95 (9): 4772--4776.
[12] Ma D W, H J Y, Ye Z Z, et al. Optical Materials, 2004, 25 (4): 367--371.
[13] Joeeph M, Tabata H, Kawai T. Appl. Phys. Lett., 1999, 74 (17): 2534--2536.
[14] Mohamed G A, Mohamed E M, El-Fadl A A. Physica B: Condensed Matter, 2001, 308-310: 949--953.
[15] Oral A Y, Asian M H, Bahsi Z B, et al. Key Engineering Materials, 2004, 264-268 (I): 415--418.
[16] El-Fadl A Abu, Mohamad Galal A, El-Moiz A B Abd, et al. Physica B : Condensed Matter, 2005, 366 (1-4): 44--54.
[17] Cui Y G, Du G T, Zhang Y T, et al. J Crystal Growth, 2005, 282 (3-4): 389--393.
[18] Lu J G, Ye Z Z, Huang J Y, et al. J. Applied Surface Science, 2003, 207 (1-4): 295--299.
[19] Sarkar A, Ghosh S, Chaudhuri S, et al. Thin Solid Films, 1991, 204 (2): 255--264.
[20] Swanepoel R. Journal of Physics E : Scientific Instruments, 1983, 16 (12): 1214--1222.
[21] 徐彭寿, 孙玉明, 施朝淑, 等. 红外与毫米波学报, 2002, 21 (S1): 91--96.
[22] Vanheusden K, Cai W L, Zhang L D. Appl. Phys. Lett., 1996, 68 (3): 403--405.
[23] 马勇, 王万录, 廖克俊, 等. 功能材料, 2004, 2 (35): 139--144.
[24] Nakagawa T, Sakaguchi I, Matsunaga K, et al. Nuclear Instruments
and Methods in Physics Research B, 2005, 232 (1-4): 343--347.