TITLE:
A Theoretical Study of Light Absorption in Self Assembled Quantum Dots
AUTHORS:
Tarek A. Ameen, Yasser M. El-Batawy, A. A. Abouelsaood
KEYWORDS:
Absorption Coefficients; Non Equilibrium Greens Function; Self Assembled Quantum Dots
JOURNAL NAME:
Optics and Photonics Journal,
Vol.3 No.2B,
July
22,
2013
ABSTRACT: Self assembled quantum dots have shown a great promise
as a leading candidate for infrared detection at room temperature. In this
paper, a theoretical model of the absorption coefficient of quantum dot devices
is presented. Both of bound to bound absorption and bound to continuum
absorption are taken into consideration in this model. This model is based on
the effective mass theory and the Non Equilibrium Greens Function (NEGF)
formalism. NEGF formalism is used to calculate the bound to continuum
absorption coefficient. The results of the model have been compared with a
published experimental work and a good agreement is obtained. Based on the
presented model, the bound to bound absorption coefficient component is compared
to the bound to continuum absorption coefficient component. In addition, the
effects of the dot dimensions and electron filling on the bound to continuum
absorption coefficient are also investigated. In general, increasing the dot
filling increases the absorption and decreasing the dots dimensions will
increase the absorption and move the absorption peak towards longer
wavelengths.