RT journal article
T1 Identification of the Segregation Kinetics of Ultrathin GaAsSb/GaAs Films Using AlAs Markers
A1 González Robledo, David
A1 Flores Gallegos, Sara
A1 Braza Blanco, María Verónica
A1 Fernández de los Reyes, Daniel
A1 Gallego Carro, Alejandro
A1 Stanojev´c, Lazar
A1 Schwarz, Malte
A1 Ulloa, Jose María
A1 Ben Fernández, Teresa
A2 Ciencia de los Materiales e Ingeniería Metalúrgica y Química Inorgánica
K1 segregation
K1 III-Sb alloys
K1 STEM analyses
AB For optoelectronic devices from the near to the far infrared, the advantages of usingultrathin III-Sb layers as quantum wells or in superlattices are well known. However, these alloyssuffer from severe surface segregation problems, so that the actual profiles are very different from thenominal ones. Here, by inserting AlAs markers within the structure, state-of-the-art transmissionelectron microscopy techniques were used to precisely monitor the incorporation/segregation of Sbin ultrathin GaAsSb films (from 1 to 20 monolayers (MLs)). Our rigorous analysis allows us to applythe most successful model for describing the segregation of III-Sb alloys (three-layer kinetic model)in an unprecedented way, limiting the number of parameters to be fitted. The simulation resultsshow that the segregation energy is not constant throughout the growth (which is not consideredin any segregation model) but has an exponential decay from 0.18 eV to converge asymptoticallytowards 0.05 eV. This explains why the Sb profiles follow a sigmoidal growth model curve with aninitial lag in Sb incorporation of 5 MLs and would be consistent with a progressive change in surfacereconstruction as the floating layer is enriched.
PB MDPI
SN 2079-4991
YR 2023
FD 2023
LK http://hdl.handle.net/10498/32439
UL http://hdl.handle.net/10498/32439
LA eng
DS Repositorio Institucional de la Universidad de Cádiz
RD 06-nov-2026