Abstracts Book - IMRC 2018

• SA6-P160
EMISSION AND STRUCTURE STUDY IN ALGAAS/GAAS QUANTUM
WELLS WITH INAS QUANTUM DOTS AND ALGAINAS STRAIN
REDUCING LAYER.
Ricardo Cisneros Tamayo 1,2 , Tetyana Torchynska 3 , Leonardo Gabriel Vega Macotela 4 , Georgiy
Polupan 5
1
ESIME CULHUACAN, Posgrado, Mexico. 2 Universidad Politécnica del Valle de México,
Nanotecnología, Mexico. 3 Escuela Superior de Física y Matemáticas IPN, Ciencia de los
Materiales, Mexico. 4 Esime zacatenco, Control, Mexico. 5 Esime zacatenco, SEPI-POSGRADO,
Mexico.
GaAs/Al0.30Ga0.70As quantum wells (QWs) with embedded InAs quantum dots
(QDs) cavered by different capping layers have been studied by means of the
photoluminescence (PL) and high resolution X-ray diffraction (HR-XRD) methods.
Three types of capping layers (GaAs, Al0.30Ga0.70As and Al0.10Ga0.75In0.15As) have
been investigated. The ground state (GS) emission band in the structure with
AlGaInAs capping is characterized by the lower peak energy, high PL intensity,
lower the full width at half maximum (FWHM) due to the smaller QD size
dispersion, in comparison with QD structures with GaAs and AlGaAs capping
layers. The analysis of PL and HR-XRD scans for the structure with AlGaInAs
capping has shown that strain relaxation at QD growth temperatures is
connected with Ga/In intermixing and manifests itself by changing material
compositions in buffer, wetting and capping layers, as well as by decreasing InAs
QD heights without changing the InAs QD material. In contrary, in the structures
with GaAs and AlGaAs capping strain relaxation is accompanied by changing
material compositions in QDs, buffer, witting and capping layers. As a result GS
emission of QDs shifts into higher energy spectral range, PL intensities fall down
and the FWHMs increase. The advantage of Al0.10Ga0.75In0.15As capping has been
discussed.
Acknowledgment:
The work was supported by the CONACYT Mexico (project 258224) and SIP-IPN,
Mexico (project 20180495).
Keywords: InAs QDs, Photoluminiscence, HRXRD
Presenting authors email: rcisnerost@msn.com