Experimental and theoretical evidence for a hydrogen stabilizedc(2×2)reconstruction of the P-rich InP(001) surface

Abstract

The formation of hydrogen bonds was investigated on the P-rich InP(001) surface employing attenuated total-reflection Fourier-transform infrared spectroscopy, low-energy electron diffraction, and total-energy density-functional theory calculations. Strong evidence was found for a $c(2\ifmmode\times\else\texttimes\fi{}2)\text{\ensuremath{-}}2\mathrm{P}\text{\ensuremath{-}}3\mathrm{H}$ reconstruction with a higher hydrogen coverage than is characteristic for the metal-organic chemical-vapor deposition prepared hydrogen-stabilized $(2\ifmmode\times\else\texttimes\fi{}2)\text{\ensuremath{-}}2\mathrm{D}\text{\ensuremath{-}}2\mathrm{H}$ surface. The new surface reconstruction was formed upon exposure to atomic hydrogen. Complete transformation of all the metastable atomic configurations to form the new surface reconstruction was not achieved, since prior to this the surface began to deteriorate. The latter effect was monitored as the formation of In-H bonds. Two observations, i.e., nearly complete screening of the infrared peaks for excitation with $p$-polarized light and a pronounced redshift of P-H peaks with increasing hydrogen coverage were attributed to dipole-dipole interaction between the vibrating adsorbates.