Incorporation of a GaAs "Extended lower barrier" in between quantum wells using nitrogen and confining layers using aluminum. Not to be confused with barrier layers used in quantum wells, the extended lower barrier is formed between the active region a nd the outer/confining layers where N and Al are respectively used. N and Al can be separated in the case where, for example, AlGaAs is being used in the confining layers and any nitrogen containing material is being used in the active region. Aluminum and Nitrogen when allowed to combine can cause deep traps and resultant non-radiative recombination, therefore N and Al pairing should be prevented. The GaAs extended barrier layer can provide a protective measure against such combination.