We have developed a quantum mechanical model for understanding and explaining the capacitance-voltage (C-V) carrier profiles observed in quantum wells (QW). The external field imposed on the QW during C-V profiling changes the carrier distribution of the system. This model considers the effects of field and quantum confinement of the carriers in the well. The results obtained by iterative solutions of Schrodinger's and Poisson's equations give a better understanding of the experiments than the previous models where quantum confinement is ignored. © 1997 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

Anomalous capacitance-voltage profiles in quantum wells explained by a quantum mechanical model

Journal of Applied Physics

InxGa1 - xN/GaN heterostructures and quantum wells (QWs) are particularly important in the application of III-V nitride materials for light emitting diodes and laser diodes. The photoluminescence (PL) emissions from InxGa1 - xN/GaN QW structures have been reported, where, for successive annealing operations, the PL peak suffers a primary red shift, followed by a blue shift. The observed phenomenon remains unexplained because of its complexity. This paper is intended towards a proper explanation of the observed experimental results through suitable quantum mechanical models and computations, whether the band gap of InN is 1.95 eV or 0.7 eV. © 2007 Elsevier B.V. All rights reserved.

Materials Letters

Unusual changes observed in the photoluminescence of annealed InxGa1 - xN/GaN quantum wells explained

Wide band-gap group-III nitrides are important for the design of optical devices in the blue and blue-green region. Owing to their wurtzite structure, these materials have a strong inherent polarization field that affects carrier distribution, exciton stability and hence influences the optical properties of the devices. So far, carriers have been assumed to have a sheet-like character. In this paper a non sheet-like distribution function for these quasi two-dimensional carriers is proposed that incorporates the effect of the polarization field. Here GaN/InGaN/GaN and AlGaN/GaN/AlGaN quantum wells have been studied. The polarization field causes the electron and hole wave functions to separate out, thus causing decrease of emission strength and strong reduction of exciton binding energy. This treatment explains well the qualitative nature of carrier distribution in the well. The polarization field changes with GaN mole fraction present in the tertiary nitride layer. The effect of mole fraction on carrier distribution has also been studied. It is found that, inside the well, the hole distribution changes a little more with change in mole fraction than the electron distribution, but for all practical purposes the net change in the distribution pattern is negligible. © 2004 Elsevier B.V. All rights reserved.

Physica E: Low-Dimensional Systems and Nanostructures

Effect of polarization on two-dimensional carrier distribution in nitride quantum wells

Band discontinuity is an important parameter for the design of heterojunction based electronic and opto-electronic devices. An alternative method for band offset measurement in quantum wells has been outlined in this paper. The band offset is determined from a comparison of experimental results and theoretical computations of the temperature dependent total charge content of a quantum well. In spite of the simplicity of the measurement procedures the result at its best has an error around ±2%.

Journal	Data powered by TypesetJournal of Applied Physics
Publisher	Data powered by TypesetAmerican Institute of Physics Inc.
ISSN	0021-8979
Open Access	No