[1] [1] KNEISSL M, SEONG T Y, HAN J, et al. The emergence and prospects of deep-ultraviolet light-emitting diode technologies［J］. Nature Photonics, 2019, 13(4): 233-244.

[3] [3] KUSCH G, NOUF-ALLEHIANI M, MEHNKE F, et al. Spatial clustering of defect luminescence centers in Si-doped low resistivity Al0.82Ga0.18N［J］. Applied Physics Letters, 2015, 107(7): 072103.

[4] [4] BONDOKOV R T, MUELLER S G, MORGAN K E, et al. Large-area AlN substrates for electronic applications: an industrial perspective［J］. Journal of Crystal Growth, 2008, 310(17): 4020-4026.

[6] [6] KHAN M A, SHATALOV M, MARUSKA H P, et al. III-nitride UV devices［J］. Japanese Journal of Applied Physics, 2005, 44(10R): 7191.

[7] [7] ZHAO D G, ZHU J J, JIANG D S, et al. Parasitic reaction and its effect on the growth rate of AlN by metalorganic chemical vapor deposition［J］. Journal of Crystal Growth, 2006, 289(1): 72-75.

[8] [8] LI J, NAM K B, LIN J Y, et al. Optical and electrical properties of Al-rich AlGaN alloys［J］. Applied Physics Letters, 2001, 79(20): 3245-3247.

[9] [9] RUSCHEL J, GLAAB J, BEIDOUN B, et al. Current-induced degradation and lifetime prediction of 310 nm ultraviolet light-emitting diodes［J］. Photonics Research, 2019, 7(7): B36-B40.

[10] [10] CHANG M H, DAS D, VARDE P V, et al. Light emitting diodes reliability review［J］. Microelectronics Reliability, 2012, 52(5): 762-782.

[11] [11] HARRIS J S, GADDY B E, COLLAZO R, et al. Oxygen and silicon point defects in Al0.65Ga0.35N［J］. Physical Review Materials, 2019, 3(5): 054604.

[12] [12] BLASCO R, AJAY A, ROBIN E, et al. Electrical and optical properties of heavily Ge-doped AlGaN［J］. Journal of Physics D: Applied Physics, 2019, 52(12): 125101.

[13] [13] WASHIYAMA S, REDDY P, SARKAR B, et al. The role of chemical potential in compensation control in Si∶AlGaN［J］. Journal of Applied Physics, 2020, 127(10): 105702.

[14] [14] CHEN H, ZHANG X, CHEN S, et al. Properties of Si-doped a-plane AlGaN layers［J］. Materials Science in Semiconductor Processing, 2020, 119: 105270.

[15] [15] TRINH X T, NILSSON D, IVANOV I G, et al. Stable and metastable Si negative-U centers in AlGaN and AlN［J］. Applied Physics Letters, 2014, 105(16): 162106.

[16] [16] LI Z H, SHAO P F, WU Y Z, et al. Plasma assisted molecular beam epitaxy growth mechanism of AlGaN epilayers and strain relaxation on AlN templates［J］. Japanese Journal of Applied Physics, 2021, 60(7): 075504.

[17] [17] ZHANG Z, LAGALLY M G. Atomic-scale mechanisms for surfactant-mediated layer-by-layer growth in homoepitaxy［J］. Physical Review Letters, 1994, 72(5): 693-696.

[18] [18] MULA G, ADELMANN C, MOEHL S, et al. Surfactant effect of gallium during molecular-beam epitaxy of GaN on AlN (0001)［J］. Physical Review B, 2001, 64(19): 195406.

[19] [19] NEUGEBAUER J, ZYWIETZ T K, SCHEFFLER M, et al. Adatom kinetics on and below the surface: the existence of a new diffusion channel［J］. Physical Review Letters, 2003, 90(5): 056101.

[20] [20] WANG J M, WANG M X, XU F J, et al. Sub-nanometer ultrathin epitaxy of AlGaN and its application in efficient doping［J］. Light: Science & Applications, 2022, 11(1): 1-8.

[21] [21] ISLAM S M, PROTASENKO V, LEE K, et al. Deep-UV emission at 219 nm from ultrathin MBE GaN/AlN quantum heterostructures［J］. Applied Physics Letters, 2017, 111(9): 091104.

[22] [22] NAKARMI M L, KIM K H, ZHU K, et al. Transport properties of highly conductive n-type Al-rich AlxGa1-xN(x≥0.7)［J］. Applied Physics Letters, 2004, 85(17): 3769-3771.

[23] [23] MEHNKE F, WERNICKE T, PINGEL H, et al. Highly conductive n-AlxGa1-xN layers with aluminum mole fractions above 80%［J］. Applied Physics Letters, 2013, 103(21): 212109.

[24] [24] COLLAZO R, MITA S, XIE J Q, et al. Progress on n-type doping of AlGaN alloys on AlN single crystal substrates for UV optoelectronic applications［J］. Physica Status Solidi C, 2011, 8(7/8): 2031-2033.

[25] [25] LIU B Y, XU F J, WANG J M, et al. Correlation between electrical properties and growth dynamics for Si-doped Al-rich AlGaN grown by metal-organic chemical vapor deposition［J］. Micro and Nanostructures, 2022, 163: 107141.