Study of phase selectivity of organic-inorganic hybrid semiconductors

A new group of hybrid organic - inorganic materials, A _IIB _VI(en) _0.5 (A = Zn and Cd and B = S, Se, and Te), have been shown to exhibit a number of unusual structurally dependent properties that are not typically found in conventional inorganic and organic materials. However, it is puzzling that for a given inorganic component the hybrid crystal comes in different phases and often favors one over another. Using first-principles methods, we study the structural and electronic properties (e.g., stability and band gap) of the three observed phases: αI, αII, and β. The general chemical trends are revealed and are consistent with experimental observations. A kinetic growth model is proposed to explain the experimental observation of the phase selection for these hybrid materials.