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Structural and electronic properties of Bi-adsorbate-stabilized reconstructions on the InP(100) and Ga As x N 1 − x ( 100 )</mml…

2006; American Physical Society; Volume: 74; Issue: 15 Linguagem: Inglês

10.1103/physrevb.74.155302

1550-235X

P. Laukkanen, Janne Pakarinen, M. Ahola-Tuomi, M. Kuzmin, R.E. Perälä, I. J. Väyrynen, Antti Tukiainen, J. Konttinen, Hanna L. Tuomisto, M. Pessa,

Advanced Chemical Physics Studies

Bismuth (Bi) adsorbate-stabilized reconstructions on the InP(100) and $\mathrm{Ga}{\mathrm{As}}_{x}{\mathrm{N}}_{1\ensuremath{-}x}(100)$ surfaces have been studied by scanning tunneling microscopy (STM) and spectroscopy (STS), x-ray photoelectron spectroscopy, and low-energy electron diffraction. With decreasing coverage, Bi is found to stabilize the $(2\ifmmode\times\else\texttimes\fi{}1)$, $(2\ifmmode\times\else\texttimes\fi{}8)$, and $(2\ifmmode\times\else\texttimes\fi{}4)$ reconstructions on the InP(100) surface and the $(2\ifmmode\times\else\texttimes\fi{}1)$ and $(2\ifmmode\times\else\texttimes\fi{}4)$ reconstructions on the $\mathrm{Ga}{\mathrm{As}}_{x}{\mathrm{N}}_{1\ensuremath{-}x}(100)$. STM results show that both the $\mathrm{Bi}∕\mathrm{In}\mathrm{P}(100)(2\ifmmode\times\else\texttimes\fi{}4)$ and $\mathrm{Bi}∕\mathrm{Ga}{\mathrm{As}}_{x}{\mathrm{N}}_{1\ensuremath{-}x}(100)(2\ifmmode\times\else\texttimes\fi{}4)$ reconstructions can be described with the $\ensuremath{\alpha}2$-like structural model. The current-voltage curves measured by STS show the $\mathrm{Bi}∕\mathrm{In}\mathrm{P}(100)(2\ifmmode\times\else\texttimes\fi{}1)$ and $\mathrm{Bi}∕\mathrm{Ga}{\mathrm{As}}_{x}{\mathrm{N}}_{1\ensuremath{-}x}(100)(2\ifmmode\times\else\texttimes\fi{}1)$ structures, which do not obey the electron counting model, to be semiconducting and metallic, respectively. Combining our experimental findings, we propose atomic models for the $(2\ifmmode\times\else\texttimes\fi{}1)$ reconstructions. An issue why Bi stabilizes unusual $(2\ifmmode\times\else\texttimes\fi{}1)$ structures is discussed.