The interplay between bandgap renormalization and Burstein-Moss effect for multilayered Al:ZnO/ZnO metamaterial

Multilayered Al:ZnO/ZnO metamaterial, a material that exhibits unique optical properties such as hyperbolic dispersion, attracted a high research interest due to its low optical loss and high conductivity. Combination of the optical gain and strong anisotropy for the Al:ZnO/ZnO metamaterial provide novel opportunities to control spontaneous emission. High doping concentrations (1020- 1021 cm-3 ) for Al:ZnO/ZnO require the inclusion the effect of the band filling. While ZnO has a large bandgap of ~3.3 eV, it has been suggested that in Al:ZnO the Burstein-Moss effect results in an increase in bandgap and thus a decrease in emitted wavelength, which may partially explain the suppression of visible photoluminescence and increase in ultraviolet photoluminescence observed in highly doped Al:ZnO. Here, we investigated the interplay between bandgap renormalization and band filling (Burstein-Moss effect). The results of our calculations show that the energy shift due to the Burstein-Moss effect (blue-shift) and bandgap renormalization (redshift) strongly depends on carrier concentration in multilayered Al:ZnO/ZnO. We found that the energy blue-shift due to BursteinMoss compensates the red-shift from the bandgap renormalization when a carrier concentration reaches 1020 cm-3 .