Semiconductor-surface restoration by valence-mending adsorbates: Application to Si(100):S and Si(100):Se

A set of criteria is proposed for choosing adsorbates that can lead to restoration of the ideal bulk-terminated geometry on semiconductor surfaces. Two systems, Si(100):S and Si(100):Se, which are likely to fulfill the surface-restoration criteria are investigated in detail through first-principles calculations. These restored surfaces are energetically stable against structural changes such as embedding the adsorbates in subsurface sites.