[1] Nakarmi M L, Nepal N, Lin J Y, et al． Photoluminescence studies of impurity transitions in Mg-doped AlGaN alloys ［J］. Appl. Phys. Lett., 2009, 94(9):091903-1-3．

[2] Narukawa Y, Kawakami Y, Funato M, et al． Role of self-formed InGaN quantum dots for exciton localization in the spatially resolved cathodoluminescence spectra of InGaN quantum wells in the purple laser diode emitting at 420 nm ［J］. Appl. Phys. Lett., 1997, 70(8):981-983．

[3] Chichibu S, Wada K, Nakamura S. Spatially resolved cathodoluminescence spectra of InGaN quantum wells ［J］. Appl. Phys. Lett., 1997, 71(16):2346-2348．

[4] Carlo A D, Sala F D, Lugli P, et al． Doping screening of polarization fields in nitride heterostructures ［J］. Appl. Phys. Lett., 2000, 76(26):3950-3952．

[5] Srinivasan B A, Plumlee C, Omiya H, et al． Exciton freeze-out and thermally activated relaxation at local potential fluctuations in thick AlxGa1-xN layers ［J］. J. Appl. Phys., 2004, 95(9):4670-4674．

[6] Nepal N, Li J, Nakarmi M L, et al. Exciton localization in AlGaN alloys ［J］. Appl. Phys. Lett., 2006, 88(6):062103-1-3．

[7] Cho Y H, Gainer G H, Lam J B, et al． Dynamics of anomalous optical transitions in AlxGa1-xN alloys ［J］. Phys. Rev. B, 2000, 61(11):7203-7206．

[8] Onuma T, Chichibu S F, Uedono A, et al． Radiative and nonradiative processes in strain-free AlxGa1-xN films studied by time-resolved photoluminescence and positron annihilation techniques ［J］. J. Appl. Phys., 2004, 95(5):2495-2504．

[9] Kazlauskas K, Ukauskas A, Tamulaitis G, et al． Exciton hopping and nonradiative decay in AlGaN epilayers ［J］. Appl. Phys. Lett., 2005, 87(17):172102-1-3．

[10] Li J, Nam K B, Lin J Y, et al． Optical and electrical properties of Al-rich AlGaN alloys ［J］. Appl. Phys. Lett., 2001, 79(20):3245-3247．

[11] Steude G, Meyer B K, Goldner A, et al． Optical investigations of AlGaN on GaN epitaxial films ［J］. Appl. Phys. Lett., 1999, 74(17):2456-2458．

[12] Lee K B, Parbrook P J, Wang T, et al． Optical investigation of exciton localization in AlxGa1-xN ［J］. J. Appl. Phys., 2007, 101(5):053513-1-6．

[13] Tansu N, Arif R A, Zhao H P, et al． Polarization engineering of iii-nitride nanostructures for high-efficiency light emitting diodes ［J］. SPIE, 2008, 70:705812-1-12．

[14] Wan S P, Xia J B, Chang K． Effects of piezoelectricity and spontaneous polarization on electronic and optical properties of wurtzite Ⅲ-Ⅴ nitride quantum wells ［J］. J. Appl. Phys., 2001, 90(12):6210-6216．

[15] Wierer J J, Fischer A J, Koleske D D． The impact of piezoelectric polarization and nonradiative recombination on the performance of (0001) face GaN/InGaN photovoltaic devices ［J］. Appl. Phys. Lett., 2010, 96(5):051107-1-3．

[16] Schwarz U T, Braun H, Kojima K, et al. Interplay of built-in potential and piezoelectric field on carrier recombination in green light emitting InGaN quantum wells ［J］. Appl. Phys. Lett., 2007, 91(12):123503-1-3．

[17] Chichibu S F, Abare A C, Minsky M S, et al． Effective band gap inhomogeneity and piezoelectric field in InGaN/GaN multi quantum well structures ［J］. Appl. Phys. Lett., 1998, 73(14):2006-2009．

[18] Nam K B, Nakarmi M L, Lin J Y, et al． Deep impurity transitions involving cation vacancies and complexes in AlGaN alloys ［J］. Appl. Phys. Lett., 2005, 86(22):222108-1-3．

[19] Zhang J, Kuokstis E, Fareed Q, et al． Pulsed atomic layer epitaxy of quaternary AlInGaN layers ［J］. Appl. Phys. Lett., 2001, 79(1):925-927．

[20] Ambacher O, Smart J, Shealy J R, et al. Two-dimensional electron gases induced by spontaneous and piezoelectric polarization charges in N- and Ga-face AlGaN/GaN heterostructures ［J］. J. Appl. Phys., 1999, 85(6):3222-3233．

[21] Takeuchi, Sota S, Katsuragawa M, et al. Quantum-confined Stark effect due to piezoelectric field in GaInN strained quantum wells ［J］. Jpn. J. Appl. Phys., 1997, 36:L382-L385．

[22] Bernardini F, Fiorentini V. Spontaneous polarization and piezoelectric constants of Ⅲ-V nitrides ［J］. Phys. Rev. B, 1997, 56(16):R10024-R10027．

[23] Lai Z Y． Polarization Field Effects on Group Ⅲ-nitride Semiconductors ［D］. Taoyuan: National Central University, 2003.

[24] Ambacher O. Growth and applications of group Ⅲ-nitrides ［J］. J. Phys. D: Appl., 1998, 31:2653-2710．

[25] Riblet P, Hirayama H, Kinoshita A, et al． Determination of photoluminescence mechanism in InGaN quantum wells ［J］. Appl. Phys. Lett., 1999, 75(1):2241-2243．

[26] Kuokstis E, Sun W H, Chen C Q, et al. Internal polarization fields in GaN/AlGaN multiple quantum wells with different crystallographic orientations ［J］. J. Appl. Phys., 2005, 97(10):103719-1-6．

[27] Liuolia V, Marcinkevicˇius S, Lin Y D, et al. Dynamics of polarized photoluminescence in m-plane InGaN/GaN quantum wells ［J］. J. Appl. Phys., 2010, 108(2):023101-1-7．

[28] Pozina G, Hemmingsson C, Forsberg U, et al. Time-resolved photoluminescence properties of AlGaN/AlN/GaN high electron mobility transistor structures grown on 4H-SiC substrate ［J］. J. Appl. Phys., 2008, 104(11):113513-1-5．

[29] Kazlauskas K, Tamulaitis G, ukauskas A, et al. Exciton and carrier motion in quaternary AlInGaN ［J］. Appl. Phys. Lett., 2003, 82(45):4501-4503．

[30] Pan X, Wang X L, Xiao H L, et al． Characteristics of high Al content AlGaN grown by pulsed atomic layer epitaxy ［J］. Appl. Surf. Sci., 2011, 257:8718-8721．

[31] Viňa L, Logothetidis S, Cardona M. Temperature dependence of the dielectric function of germanium ［J］. Phys. Rev. B, 1984, 30(4):1979-1991．

[32] Singh M. Magneto-optics of semiconductors with double-hump and nonparabolic band structures ［J］. Phys. Rev. B, 1987, 35(18):9714-9721．

[33] Li C F, Huang Y S, Malikova L, et al． Temperature dependence of the energies and broadening parameters of the interband excitonic transitions in wurtzite GaN ［J］. Phys. Rev. B, 1997, 55(15):9251-9254．

[34] Li J, Nam K B, Nakarmi M L, et al． Band structure and fundamental optical transitions in wurtzite AlN ［J］. Appl. Phys. Lett., 2003, 83(25):5163-5165．

[35] Bergman J P, Lundstrm T, Monemar B, et al． Photoluminescence related to the two dimensional electron gas at a GaN/AlGaN heterointerface ［J］. Appl. Phys. Lett., 1996, 69(23):3456-3458．

[36] Cho Y H, Gainer G H, Fischer A J, et al．“S-shaped'” temperature-dependent emission shift and carrier dynamics in InGaN/GaN multiple quantum wells ［J］. Appl. Phys. Lett., 1998, 73(10):1370-1372．