The discrepancies between theory and experiment in the optical emission of monolayer In(Ga)N quantum wells revisited by transmission electron microscopy

Quantitative high resolution transmission electron microscopy studies of intentionally grown 1InN/nGaN short-period superlattices (SLs) were performed. The structures were found to consist of an InxGa1−xN monolayer with an Indium content of x = 0.33 instead of the intended x = 1. Self-consistent calculations of the band structures of 1In0.33Ga0.67N/nGaN SLs were carried out, including a semi-empirical correction for the band gaps. The calculated band gap, Eg, as well as its pressure derivative, dEg/dp, are in very good agreement with the measured photoluminescence energy, EPL, and its pressure derivative, dEPL/dp, for a series of 1In0.33Ga0.67N/nGaN samples with n ranging from 2 to 40. This resolves a discrepancy found earlier between measured and calculated optical emission properties, as those calculations were made with the assumption of a 1InN/nGaN SL composition