[1] [1] YU R X, LIU G X, WANG G D, et al. Ultrawidebandgap semiconductor AlN crystals: growth and applications［J］. Journal of Materials Chemistry C, 2021, 9(6): 18521873.

[3] [3] TANIYASU Y, KASU M, MAKIMOTO T. An aluminium nitride lightemitting diode with a wavelength of 210 nanometres［J］. Nature, 2006, 441(7091): 325328.

[4] [4] ZHOU Q, WU H L, LI H, et al. Barrier inhomogeneity of Schottky diode on nonpolar AlN grown by physical vapor transport［J］. IEEE Journal of the Electron Devices Society, 2019, 7: 662667.

[5] [5] REDDY P, HAYDEN BRECKENRIDGE M, GUO Q A, et al. High gain, large area, and solar blind avalanche photodiodes based on Alrich AlGaN grown on AlN substrates［J］. Applied Physics Letters, 2020, 116(8): 081101.

[6] [6] SLACK G A, MCNELLY T F. Growth of high purity AlN crystals［J］. Journal of Crystal Growth, 1976, 34(2): 263279.

[7] [7] SCHUJMAN S B, SCHOWALTER L J, BONDOKOV R T, et al. Structural and surface characterization of large diameter, crystalline AlN substrates for device fabrication［J］. Journal of Crystal Growth, 2008, 310(5): 887890.

[8] [8] DALMAU R, CRAFT H S, BRITT J, et al. High quality AlN single crystal substrates for AlGaNbased devices［J］. Materials Science Forum, 2018, 924: 923926.

[9] [9] WANG Q K, LEI D, HUANG J L, et al. Homoepitaxial growth of 3inch single crystalline AlN boules by the physical vapor transport process［J］. Frontiers in Materials, 2023, 9: 1128468.

[10] [10] JIN L, ZHAO K, XU S H, et al. Optical property in colorless AlN bulk crystals: investigation of native defectinduced UV absorption［J］. Scripta Materialia, 2021, 190: 9196.

[11] [11] ZHAO Q Y, ZHU X Y, HAN T, et al. Realizing overgrowth in the homoPVT process for 2 inch AlN single crystals［J］. CrystEngComm, 2022, 24(9): 17191724.

[12] [12] ZHANG L, QI H T, CHENG H J, et al. Preparation and characterization of AlN seeds for homogeneous growth［J］. Journal of Semiconductors, 2019, 40(10): 102801.

[13] [13] WANG G D, ZHANG L, WANG Y, et al. Effect of temperature gradient on AlN crystal growth by physical vapor transport method［J］. Crystal Growth & Design, 2019, 19(11): 67366742.

[14] [14] HU W J, GUO L W, GUO Y L, et al. Growing AlN crystals on SiC seeds: effects of growth temperature and seed orientation［J］. Journal of Crystal Growth, 2020, 541: 125654.

[15] [15] SUMATHI R R, BARZ R U, GILLE P, et al. Influence of interface formation on the structural quality of AlN single crystals grown by sublimation method［J］. Physica Status Solidi C, 2011, 8(7/8): 21072109.

[16] [16] SUMATHI R R. Bulk AlN single crystal growth on foreign substrate and preparation of freestanding native seeds［J］. CrystEngComm, 2013, 15(12): 22322240.

[17] [17] HARTMANN C, WOLLWEBER J, SINTONEN S, et al. Preparation of deep UV transparent AlN substrates with high structural perfection for optoelectronic devices［J］. CrystEngComm, 2016, 18(19): 34883497.

[18] [18] WANG Q K, LEI D, HE G D, et al. Characterization of 60 mm AlN single crystal wafers grown by the physical vapor transport method［J］. Physica Status Solidi (a), 2019, 216(16): 1970052.

[19] [19] HABOECK U, SIEGLE H, HOFFMANN A, et al. Lattice dynamics in GaN and AlN probed with first and secondorder Raman spectroscopy［J］. Physica Status Solidi (c), 2003(6): 17101731.

[20] [20] DAVYDOV V Y, KITAEV Y E, GONCHARUK I N, et al. Phonon dispersion and Raman scattering in hexagonal GaN and AlN［J］. Physical Review B, 1998, 58(19): 1289912907.

[21] [21] FU D Y, LEI D, LI Z, et al. Toward Φ56 mm Alpolar AlN single crystals grown by the homoepitaxial PVT method［J］. Crystal Growth & Design, 2022, 22(5): 34623470.

[22] [22] SARUA A, KUBALL M, VAN NOSTRAND J E. Deformation potentials of the E2(high) phonon mode of AlN［J］. Applied Physics Letters, 2002, 81(8): 14261428.

[23] [23] HARTMANN C, KABUKCUOGLU M P, RICHTER C, et al. Efficient diameter enlargement of bulk AlN single crystals with high structural quality［J］. Applied Physics Express, 2023, 16(7): 075502.

[24] [24] RAGHOTHAMACHAR B, YANG Y, DALMAU R, et al. Defect generation mechanisms in PVTgrown AlN single crystal boules［J］. Materials Science Forum, 2013, 740/741/742: 9194.

[25] [25] BICKERMANN M, EPELBAUM B M, WINNACKER A. Characterization of bulk AlN with low oxygen content［J］. Journal of Crystal Growth, 2004, 269(2/3/4): 432442.

[26] [26] HARRIS J H, YOUNGMAN R A, TELLER R G. On the nature of the oxygenrelated defect in aluminum nitride［J］. Journal of Materials Research, 1990, 5(8): 17631773.

[27] [27] ROSENBERGER L, BAIRD R, MCCULLEN E, et al. XPS analysis of aluminum nitride films deposited by plasma source molecular beam epitaxy［J］. Surface and Interface Analysis, 2008, 40(9): 12541261.

[28] [28] ALEVLI M, OZGIT C, DONMEZ I, et al. Structural properties of AlN films deposited by plasmaenhanced atomic layer deposition at different growth temperatures［J］. Physica Status Solidi (a), 2012, 209(2): 266271.

[29] [29] KUANG X P, ZHANG H Y, WANG G G, et al. AlN films prepared on 6HSiC substrates under various sputtering pressures by RF reactive magnetron sputtering［J］. Applied Surface Science, 2012, 263: 6268.

[30] [30] SEDHAIN A, LIN J Y, JIANG H X. Nature of optical transitions involving cation vacancies and complexes in AlN and AlGaN［J］. Applied Physics Letters, 2012, 100(22): 221107.

[31] [31] LIU G, YAN C Y, ZHOU G G, et al. Broadband whitelight emission from alumina nitride bulk single crystals［J］. ACS Photonics, 2018, 5(10): 40094013.