Growth modes of Se overlayers deposited on Au(111) surfaces

The growth processes of Se overlayers deposited on Au(111) surfaces have been investigated using in situ Auger electron spectroscopy (AES), low-energy electron diffraction (LEED) and electron energy loss spectroscopy (EELS), The Au(111) substrate was formed in situ by vacuum deposition on an air-cleaved MoS2 substrate at 590 K in an ultrahigh vacuum chamber. AES and EELS results can be interpreted by assuming the growth of Frank-van der Merwe mode for the first 3 overlayers at a substrate temperature of 298 K. LEED patterns also indicate that the Au(111)-(root 3 x root 3)R30 degrees-Se structure is formed at the first monolayer, and that the (1 x root 7)R79.1 degrees-Se structure is formed ranging from the second to third layer. The (1 x root 7)R79.1 degrees structure fades out during formation of the fourth layer. When the Se is deposited at elevated temperature, the growth of overlayers is restricted due to reevaporation of Se. (C) 1997 Elsevier Science B.V.