Design Guidelines for True Green LEDs and High efficiency Photovoltaics Using ZnSe/GaAs Digital Alloys

In the fields of solid state lighting and high efficiency solar photovoltaics (PV), a need still exists for a material system that can target the 2.3-2.5eV energy range. The ZnSe/GaAs system is shown to have great potential. The digital alloy approach can be utilized as a well-ordered design alternative to the disordered alloyed systems. The effective band-gap of the ZnSe/GaAs(001) superlattice has been studied, as a function of the constituent monolayers using tight binding. The possibility of engineering a range of band-gaps with the same material system, to achieve the optimum value for solar PV and LED applications, has been proposed.