The advancement in the fabrication of low-dimensional semiconductor structures has made it possible to grow zero-dimensional electron-hole systems called quantum dots (QDs). In recent years, there have been extensive studies on III-V semiconductor QDs. In this paper, we have formulated the absorption spectra of realistic QD systems with dot size distribution described by a Gaussian function. The dots were approximated as cubic boxes having finite potentials at the boundaries. The effects of size nonuniformity on the optical absorption spectra of few realistic QD systems were analyzed, and the results have been compared with ideal dots having infinite potentials at the boundaries. © 2007 American Institute of Physics.

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University of Calcutta (informally known as Calcutta University or CU) is a collegiate public state university located in Kolkata, West Bengal, India.&nbsp;Within India it is recognized as a &quot;Five-Star University&quot; and accredited &quot;A&quot; Grade by National Assessment and Accreditation Council.

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The University of Calcutta has secured the Fifth position among the Universities of India in the prestigious &quot;Indian University Ranking 2019&quot; list, released by the NIRF of the Ministry of Human Resource Development, Government of India.

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It was established on 24 January 1857, and was one of the first institutions in Asia to be established as a multidisciplinary and Western-style university. Its alumni and faculty include several heads of state, heads of government, social reformers, prominent artists, only academy award winner and Dirac medal winner in India, many Fellows of the Royal Society and five Nobel laureates as of 2019 which is highest in South Asia.

University Of Calcutta

Effects of a Gaussian size distribution on the absorption spectra of III-V semiconductor quantum dots

Journal of Applied Physics

InAs/GaAs quantum dots (QDs) grown by various methods do not have the same dimensions in the three axes. This paper reports on expressions for computations of the optical transitions and absorption spectra of InAs/GaAs QDs that have a square base and the variation of the height is Gaussian. The dots were considered to be elongated quantum boxes with square bases having finite potentials at the boundaries. The results are in excellent agreement with reported experimental data of photoluminescence and absorption. The expressions could be successfully applied to short quantum wires. © 2011 American Institute of Physics.

Computations of the optical transitions and absorption spectra in a set of realistic, elongated InAs/GaAs quantum boxes having a Gaussian distribution

The absorption spectra of semiconductor quantum dots (QDs) are expected to be a series of δ-function-like discrete lines due to the nature of the density of states. In a realistic IIIV QD system, the absorption spectra is the superimposition of the contribution from each individual dot and the overall behavior is modeled by considering a Gaussian size distribution. In this paper, we study and present the dependence of the Gaussian nature of the absorption spectra of InXGa1-XN/GaN QD systems on the dot size distribution and some fundamental parameters such as bowing effect of the band gap, band offset ratio, and so on. It is observed that the absorption spectra depend strongly on the dot size distribution. The results presented helps to get a better insight of the optical properties of InXGa 1-XN/GaN QD systems. © 2010 World Scientific Publishing Company.

International Journal of Nanoscience

Dependence of the absorption spectra of IIIV semiconductor quantum dots on the fundamental parameters

Recently InXGa1-XN/GaN heterostructures and quantum wells (QWs) have gained immense importance in the application of III-V nitride materials. Reported values of the ratios of conduction band offset to valence band offset for InXGa1-XN/GaN QW structures, ΔEc:ΔEv, vary widely from 38:62 to 83:17. While trying to explain the unusual shifts in the photoluminescence (PL) spectra, obtained from InXGa1-XN/GaN QW structures, it has been found that a band offset ratio, ΔEc:ΔEv = 55:45, explains all the experimental data precisely. In this paper detailed theories, procedures, results and discussions to establish the newly estimated band offsets will be presented. © 2006 Elsevier B.V. All rights reserved.

Journal	Journal of Applied Physics
Publisher	AMER INST PHYSICS
ISSN	0021-8979
Open Access	No