Title :
Structural and optical properties of multi-stack InAs/GaAsSb quantum dots with different Sb composition
Author :
Yeongho Kim ; Faleev, Nikolai ; Dinghao Tang ; Smith, D. ; Kuciauskas, Darius ; Dippo, Patricia C. ; Honsberg, C.
Author_Institution :
Sch. of Electr., Comput. & Energy Eng., Arizona State Univ., Tempe, AZ, USA
Abstract :
The impact of the Sb composition on the structural and optical properties of ten-stack InAs/GaAsSb quantum dots (QDs) were investigated using transmission electron microscopy (TEM), high-resolution x-ray diffraction (XRD), and photoluminescence (PL). The TEM images demonstrate that the Sb composition affects the change in the QD density and morphology. From analysis of XRD reciprocal space maps (RSMs) of the (224) asymmetrical reflection, it is found that as the Sb composition increases the relaxation of the initial elastic stress of the GaAsSb increases up to 23 %. In addition, the Sb composition influences the interband optical transitions such as the PL peak redshift and carrier lifetimes.
Keywords :
III-V semiconductors; X-ray diffraction; carrier lifetime; carrier relaxation time; crystal morphology; gallium arsenide; indium compounds; photoluminescence; red shift; semiconductor quantum dots; transmission electron microscopy; InAs-GaAsSb; PL peak redshift; QD density; QD morphology; RSM; Sb composition; TEM; XRD reciprocal space maps; asymmetrical reflection; carrier lifetimes; elastic stress; high-resolution X-ray diffraction; multistack InAs-GaAsSb quantum dots; optical properties; photoluminescence; relaxation; structural properties; transmission electron microscopy; Energy efficiency; Indexes; Lead; Monitoring; Optical diffraction; Optical imaging; X-ray scattering; carrier lifetime; crystalline defects; intermediate band solar cells; photoluminescence; quantum dots;
Conference_Titel :
Photovoltaic Specialist Conference (PVSC), 2014 IEEE 40th
Conference_Location :
Denver, CO
DOI :
10.1109/PVSC.2014.6925095
