[1] [1] HUFFAKER D L, PARK G, ZOU Z, et al. 1.3 μm room-temperature GaAs-based quantum-dot laser［J］. Applied Physics Letters, 1998, 73(18): 2564-2566.

[2] [2] LIAO M Y, CHEN S M, LIU Z X, et al. Low-noise 1.3 μm InAs/GaAs quantum dot laser monolithically grown on silicon［J］. Photonics Research, 2018, 6(11): 1062-1066.

[3] [3] YIFAT Y, ACKERMAN M, GUYOT-SIONNEST P. Mid-IR colloidal quantum dot detectors enhanced by optical nano-antennas［J］. Applied Physics Letters, 2017, 110(4): 041106.

[4] [4] YOON S, LEE S H, SHIN J C, et al. Photoreflectance study on the photovoltaic effect in InAs/GaAs quantum dot solar cell［J］. Current Applied Physics, 2018, 18(6): 667-672.

[5] [5] EGOROV A Y, BEDAREV D, BERNKLAU D, et al. Self-assembled InAs quantum dots in an InGaAsN matrix on GaAs［J］. Physica Status Solidi (b), 2001, 224(3): 839-843.

[6] [6] STROM N W, WANG Z M, LEE J H, et al. Self-assembled InAs quantum dot formation on GaAs ring-like nanostructure templates［J］. Nanoscale Research Letters, 2007, 2(2): 112-117.

[7] [7] GARCiA J M, GRANADOS D, SILVEIRA J P, et al. In segregation effects during quantum dot and quantum ring formation on GaAs(001)［J］. Microelectronics Journal, 2004, 35(1): 7-11.

[8] [8] SU L L, WANG Y, GUO Q L, et al. Optical characterization of type-I to type-II band alignment transition in GaAs/AlxGa1-xAs quantum rings grown by droplet epitaxy［J］. Journal of Physics D: Applied Physics, 2017, 50(32): 32LT01.

[9] [9] SUZUKI T, NISHINAGA T. Real time observation and formation mechanism of Ga droplet during molecular beam epitaxy under excess Ga flux［J］. Journal of Crystal Growth, 1994, 142(1/2): 61-67.

[10] [10] JO M, MANO T, SAKUMA Y, et al. Extremely high-density GaAs quantum dots grown by droplet epitaxy［J］. Applied Physics Letters, 2012, 100(21): 212113.

[11] [11] BENYOUCEF M, ZUERBIG V, REITHMAIER J P, et al. Single-photon emission from single InGaAs/GaAs quantum dots grown by droplet epitaxy at high substrate temperature［J］. Nanoscale Research Letters, 2012, 7(1): 493.

[12] [12] YU P, WU J, GAO L, et al. InGaAs and GaAs quantum dot solar cells grown by droplet epitaxy［J］. Solar Energy Materials and Solar Cells, 2017, 161: 377-381.

[13] [13] PANKAOW N, PANYAKEOW S, RATANATHAMMAPHAN S. Formation of In0.5Ga0.5As ring-and-hole structure by droplet molecular beam epitaxy［J］. Journal of Crystal Growth, 2009, 311(7): 1832-1835.

[14] [14] ABUWAAR Z Y, MAZUR Y I, LEE J H, et al. Optical behavior of GaAsAlGaAs ringlike nanostructures［J］. Journal of Applied Physics, 2007, 101(2): 024311.

[15] [15] KANJANACHUCHAI S, EUARUKSAKUL C. Self-running Ga droplets on GaAs (111)A and (111)B surfaces［J］. ACS Applied Materials & Interfaces, 2013, 5(16): 7709-7713.

[16] [16] TRISNA B A, NAKARESEISOON N, EIWWONGCHAROEN W, et al. Reliable synthesis of self-running Ga droplets on GaAs (001) in MBE using RHEED patterns［J］. Nanoscale Research Letters, 2015, 10(1): 184.

[17] [17] TANG W X, ZHENG C X, ZHOU Z Y, et al. Ga droplet surface dynamics during Langmuir evaporation of GaAs［J］. IBM Journal of Research and Development, 2011, 55(4): 10: 1-10: 7.

[18] [18] ROSINI M, MAGRI R, KRATZER P. Adsorption of indium on an InAs wetting layer deposited on the GaAs(001) surface［J］. Physical Review B, 2008, 77(16): 165323.

[19] [19] ESSER N, FRISCH A M, RSELER A, et al. Optical resonances of indium islands on GaAs(001) observed by reflectance anisotropy spectroscopy［J］. Physical Review B, 2003, 67(12): 125306.

[20] [20] MANTOVANI V, SANGUINETTI S, GUZZI M, et al. Low density GaAsAlGaAs quantum dots grown by modified droplet epitaxy［J］. Journal of Applied Physics, 2004, 96(8): 4416-4420.

[21] [21] MANO T, KURODA T, MITSUISHI K, et al. GaAsAlGaAs quantum dot laser fabricated on GaAs (311)A substrate by droplet epitaxy［J］. Applied Physics Letters, 2008, 93(20): 203110.

[22] [22] WU J, WANG Z M, LI A Z, et al. Surface mediated control of droplet density and morphology on GaAs and AlAs surfaces［J］. Physica Status Solidi (RRL) - Rapid Research Letters, 2010, 4(12): 371-373.

[23] [23] LI A Z, WANG Z M, WU J, et al. Holed nanostructures formed by aluminum droplets on a GaAs substrate［J］. Nano Research, 2010, 3(7): 490-495.

[24] [24] PONCE F, EGLASH S. Lattice structure and electrical properties of epitaxial aluminum on GaAs［J］. Thin Solid Films, 1983, 104(3/4): 317.

[25] [25] LI H O, CAO G, XIAO M, et al. Fabrication and characterization of an undoped GaAs/AlGaAs quantum dot device［J］. Journal of Applied Physics, 2014, 116(17): 174504.

[26] [26] AVERY A R, DOBBS H T, HOLMES D M, et al. Nucleation and growth of Islands on GaAs surfaces［J］. Physical Review Letters, 1997, 79(20): 3938.

[27] [27] KLEY A, RUGGERONE P, SCHEFFLER M. Novel diffusion mechanism on the GaAs(001) surface: the role of adatom-dimer interaction［J］. Physical Review Letters, 1997, 79(26): 5278.

[28] [28] VENABLES J A, SPILLER G T, HANBUCKEN M. Nucleation and growth of thin films［J］. Reports on Progress in Physics, 1984, 47(4): 399-459.

[29] [29] VENABLES J A, PERSAUD R, METCALFE F L, et al. Rate and diffusion analyses of surface processes［J］. Journal of Physics and Chemistry of Solids, 1994, 55(10): 955-964.

[30] [30] LABELLA V P, BULLOCK D W, EMERY C, et al. Enabling electron diffraction as a tool for determining substrate temperature and surface morphology［J］. Applied Physics Letters, 2001, 79(19): 3065-3067.

[31] [31] LEE J H, LEE J H, WANG ZHM, et al. Size and density control of In droplets at near room temperatures［J］. Nanotechnology, 2009, 20(28): 285602.

[32] [32] HATA M, WATANABE A, ISU T. Surface diffusion length observed by in situ scanning microprobe reflection high-energy electron diffraction［J］. Journal of Crystal Growth, 1991, 111(1/2/3/4): 83-87.

[33] [33] MANO T, KURODA T, MITSUISHI K, et al. High-density GaAs/AlGaAs quantum dots formed on GaAs (311)A substrates by droplet epitaxy［J］. Journal of Crystal Growth, 2009, 311(7): 1828-1831.