WANG Yu-chao, WU Tian-zhun, SU Long-xing, ZHANG Quan-lin, CHEN Ming-ming, TANG Zi-kang. Luminescence Characteristics of High-quality ZnO and BeZnO Films[J]. Chinese Journal of Luminescence, 2013,34(8): 1035-1039
WANG Yu-chao, WU Tian-zhun, SU Long-xing, ZHANG Quan-lin, CHEN Ming-ming, TANG Zi-kang. Luminescence Characteristics of High-quality ZnO and BeZnO Films[J]. Chinese Journal of Luminescence, 2013,34(8): 1035-1039 DOI: 10.3788/fgxb20133408.1035.
Luminescence Characteristics of High-quality ZnO and BeZnO Films
-plane sapphire substrate using plasma-assisted molecular beam epitaxy (P-MBE) by inserting metal oxide buffer layers. X-ray diffraction(XRD) results show that all films have hexagonal wurtzite structure and highly
c
-axis orientation. The full width at half maximum (FWHM) of ZnO film is as low as 108 arcsec
and the FWHM of BeZnO film is less than 600 arcsec. The resonance Raman spectra show that both A
1
(LO) and A
1
(2LO) phonon modes shift to larger wavenumber with more Be doping. For the first time
the local vibration mode related to Be doping is found. The photoluminescence (PL) spectrum of ZnO films has only one emission peak(378 nm) at room temperature. However
another peak due to the strong free exciton emission is observed at low temperature (80 K). With the temperature increasing
the free exciton emission dominated over the bound exciton emission
and its peak shows gradual red shift. As for BeZnO film
the strong free exciton emission peak is not found at low temperature (80 K) due to the declined crystal quality caused by the incorporation of Be. It is also found that the peak position of BeZnO films in the PL and Raman spectra have local maximum values between 100~200 K
which is suggested to be caused by the stress effect due to the thermal expansion mismatch of the alloy lattices.
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references
Tang Z K, Wong G K L, Yu P, et al. Room-temperature ultraviolet laser emission from self-assembled ZnO microcrystallite thin films [J]. Appl. Phys. Lett., 1998, 72(25):3270-3272.[2] Fan X W. Research progress on growth and optical properties of wide band gap Ⅱ-Ⅵ compound semiconductors and its low dimensional structure [J]. Chin. J. Lumin.(发光学报), 2002, 23(4):17-324 (in Chinese).[3] Bagnall D M, Chen Y F, Zhu Z, et al. Optically pumped lasing of ZnO at room temperature [J]. Appl. Phys. Lett., 1997, 70(17):2230-2232.[4] Tsukazaki A, Ohtomo A, Onuma T, et al. Repeated temperature modulation epitaxy for p-type doping and light-emitting diode based on ZnO [J]. Nat. Mater., 2005, 4(1):42-46.[5] Look D C. Recent advances in ZnO materials and devices [J]. Mater. Sci. Eng. B, 2001, 80(1-3):83-87.[6] Bagnall D M, Chen Y F, Zhu Z, et al. High temperature excitonic stimulated emission from ZnO epitaxial layers [J]. Appl. Phys. Lett., 1998, 73(8):1038-1040.[7] Asahara H, Takamizu D, Inokuchi A, et al.Characterization of MgZnO films grown by plasma enhanced metal-organic chemical vapor deposition [J]. Thin Solid Films, 2010, 518(11):2953-2956.[8] zgr , Alivov Y I, Liu C, et al. A comprehensive review of ZnO materials and devices [J]. J. Appl. Phys., 2005, 98(4):041301-1-3.[9] Ohtomo A, Kawasaki M, T Koida, et al. MgxZn1-xO as a Ⅱ-Ⅵ wide gap semiconductor alloy [J]. Appl. Phys. Lett., 1998, 72(19):2466-2468.[10] Makino T, Segawa Y, Kawasaki M, et al. Band gap engineering based on MgxZn1-xO and CdyZn1-yO ternary alloy films [J]. Appl. Phys. Lett., 2001, 78(9):1237-1239.[11] Ju Z G, Shan C X, Jiang D Y, et al. MgxZn1-xO-based photodetectors covering the whole solar-blind spectrum range [J]. Appl. Phys. Lett., 2008, 93(17):173505-1-3.[12] Du X, Mei Z, Liu Z, et al. Controlled growth of high-quality ZnO-based films and fabrication of visible-blind and solar-blind ultra-violet detectors [J]. Adv. Mater., 2009, 21(45):4625-4630.[13] Wei Z P, Wu C X, Lu Y M, et al. MgxZn1-xO alloy grown by p-MBE and optical properties of MgZnO/ZnO heterostructure [J]. Chin. J. Lumin.(发光学报), 2006, 27(5):832-833 (in Chinese).[14] Zhu H, Shan C X, Li B H, et al. Enhanced photoluminescence caused by localized excitons observed in MgZnO alloy [J]. J. Appl. Phys., 2009, 105(10):103508-1-5.[15] Ryu Y R, Lee T S, Lubguban J A, et al. Wide-band gap oxide alloy: BeZnO [J]. Appl. Phys. Lett., 2006, 88(5):052103-1-3.[16] Li X P, Cao P J, Su S C, et al. Investigation on near band edge UV luminescence of ZnO thin films [J]. Chin. J. Lumin.(发光学报), 2012, 33(5):482-484 (in Chinese).[17] Shi C S, Zhang G B, Chen Y H, et al. Special spectroscopic properties of ZnO thin film and its mechanisms [J]. Chin. J. Lumin.(发光学报), 2004, 25(3):273-275 (in Chinese).[18] Hamby D W, Lucca D A, Klopfstein M J, et al. Temperature dependent exciton photoluminescence of bulk ZnO [J]. J. Appl. Phys., 2003, 93(6):3214-3217.[19] Rieger W, Metzger T, Angerer H, et al. Influence of substrate induced biaxial compressive stress on the optical properties of thin GaN films [J]. Appl. Phys. Lett., 1996, 68(7):970-972.[20] Cusc R, Alarcn-Llad E, Ibez J, et al. Temperature dependence of Raman scattering in ZnO [J]. Phys. Rev. B, 2007, 75(16):165202-1-11.[21] Calleja J M, Cardona M. Resonant Raman scattering in ZnO [J]. Phys. Rev. B, 1977, 16(8):3753-3761.[22] Guo L L, Zhang Y H, Shen W Z. Temperature dependence of Raman scattering in GaMnN [J]. Appl. Phys. Lett., 2006, 89(16):161920-1-3.[23] Link A, Bitzer K, Limmer W, et al. Temperature dependence of the E2 and A1(LO) phonons in GaN and AlN [J]. J. Appl. Phys., 1999, 86(11):6256-6260.[24] Bundesmann C, Rahm A, Lorenz M, et al. Infrared optical properties of MgxZn1-xO thin films (0x 1): Long-wavelength optical phonons and dielectric constants [J]. J. Appl. Phys., 2006, 99(11):113504-1-11.[25] Huang Y, Liu M, Li Z, et al. Raman spectroscopy study of ZnO-based ceramic films fabricated by novel sol-gel process [J]. Mater. Sci. Eng, B, 2003, 97(2):111-116.