Density Functional Calculation of the 0.5ML-Terminated Allyl Mercaptan/Si(100)-(2×1) Surface

The structural and electronic properties of the 0.5ML-terminated allyl mercaptan (ALM)/Si(100)-(2×1) surface are studied using the density functional method. The calculated absorption energy of the ALM molecule on the 0.5ML-terminated ALM/Si(100)-(2×1) surface is 3.36eV, implying that adsorption is strongly favorable. The electronic structure calculations show that the ALM/Si(100)-(2×1), the clean Si(100)-(2×1), and the fully-terminated H/Si(100)-(2×1) surfaces have the nature of an indirect band gap semiconductor. The highest occupied molecular orbital is dominated by the ALM, confirming the mechanism proposed by Hossain for its chain reaction.