Abstract
InAsBi/InAs heterostructures were elaborated on semi-insulating GaAs substrate by atmospheric pressure metalorganic vapor phase epitaxy. Spectral reflectance in the range of 400–800 nm was employed to in situ monitor epitaxy. In order to determine optical constants of InAsBi films, an optical model incorporating two parameters: time-dependent surface roughness and time-dependent growth rate was established to simulate the in situ reflectance. Since bismuth has a crucial effect on surface kinetic mechanisms during growth of III–V semiconductors, a theoretical motivation introducing these two parameters instead of a standard single rms roughness and growth rate was provided. In order to evaluate the structural and optical properties of this material, reflectivity responses were analyzed for several wavelengths. Results were ex situ correlated with atomic force microscopy measurements.