Structural and Electronic Properties of a Wide-gap Semiconductor Alloy: Zn_xMg_{1-x}S_ySe_{1-y}

摘要

The structural properties of the $Zn_xMg_{1-xS_ySe_{1-y}}$ solid solutionsare determined by a combination of the computational alchemy and the clusterexpansion methods with Monte Carlo simulations. We determine the phase diagramof the alloy and show that the homogeneous phase is characterized by a largeamount of short-range order occurring among first-nearest neighbors.Electronic-structure calculations performed using the special quasi-randomstructures approach indicate that the energy gap of the alloy is rathersensitive to this short-range order.