화학공학소재연구정보센터
Applied Surface Science, Vol.485, 29-34, 2019
Modelling of bismuth segregation in InAsBi/InAs superlattices: Determination of the exchange energies
InAsBi dilute alloys are potential new candidates for the improvement of infrared optoelectronic devices such as photodetectors or lasers. In this work, InAsBi/InAs superlattices (SLs) with Bi contents ranging between 1 and 3% were grown by molecular beam epitaxy with different Bi fluxes and growth temperatures to analyze Bi segregation by cross sectional transmission electron microscopy techniques. Bi segregation profiles have been described layer-by-layer using a three-layer fluid exchange mechanism, extracting the values of the As/Bi exchange energies (E-1, 1.26 +/- 0.01 eV and E-2, 1.36 +/- 0.02 eV). A relationship to calculate the activation energies for exchange from the binding energies in III-V alloys is proposed, which would allow predicting them for other hitherto unknown compounds.