Out of plane screening and dipolar interactions in heterostructures

Out-of-plane screening (OPS) is expected to occur generally in metal-semiconductor interfaces but this aspect has been overlooked in previous studies. In this paper we study the effect of OPS in electron-hole bilayer (EHBL) systems. The validity of the dipolar interaction induced by OPS is justified with a RPA calculation. Effect of OPS in electron-hole liquid with close-by screening layers is studied. We find that OPS affects the electronic properties in low density and long wavelength regime. The corresponding zero-temperature phase diagram is obtained within a mean field treatment. We argue that our result is in general relevant to other heterostrucutures. The case of strongly correlated EHBL is also discussed.