The influence of AuNs on the optical properties of GaAs/AlGaAs tunnel-coupled quantum well

Abstract

Abstract Using a numerical approach, we investigated a GaAs/AlGaAs tunnel-coupled quantum well (TCQW) to examine the interplay between electromagnetic waves and gold nanospheres (AuNs) in the presence of an extra SiO2 layer and surface roughness. Our findings demonstrated that the optical efficiency of the response of AuNs was increased in the presence of the SiO2 layer. The extinction cross-section also increased in the presence of surface roughness. Furthermore, we discovered that the orientation of AuNs on the rough surface of TCQW can give rise to a new mode of resonant frequency in the near infrared range. This new mode is advantageous for the TCQW as it is usually seen in AuNs only in the visible range. Lastly, the energy level and wave function of electrons in the TCQW intersubband could be adjusted by an electric field produced by the presence of AuNs. Therefore, this theoretical study could be applied to improve output efficiency and the tuning of performances of optical devices such as solar cells and tunable wavelength photoemitters.