THEORETICAL ESTIMATION OF LEAKAGE CURRENT IN II-VI HETEROSTRUCTURE LASERS

II-VI heterostructures studied in terms of lasing properties up to now have been mostly common-anion or common-cation heterostructures, where the band offsets are localized either in the conduction band or in the valence band. This paper deals with a leakage current in this sort of p-i-n heterostructure under forward bias. It is shown that the leakage current does not necessarily depend on the band offset, but principally depends on the energy-gap difference between the active layer and the cladding layer. This result leads to the expectation that the above heterostructures with the nearly flat band structures either in the conduction band or in the valence band will be applicable as II-VI laser materials. Quantitative comparison between the radiative recombination current and the leakage current was also performed on the laser diode structure.