First principles study on the electronic structures of narrow-band spherical quantum dots in direct silicon nanocrystal-insulator systems

• Main Author: , Kamsu! Abraha, Muhamad Darwis Umar, and Mirza Satriawan
• Format: Article NonPeerReviewed
• Published: [Yogyakarta] : Fak. MIPA UGM 2007
• Online Access: https://repository.ugm.ac.id/93866/; http://repository.ugm.ac.id/digitasi/index.php?module=cari_hasil_full&idbuku=1661
• Institution: Universitas Gadjah Mada

<p>We present first principles calculations of the electronic structures of spherically<br /> symmetricquantum dots (QDs) in direct-bandgap silicon nanocrystals which are potentially<br /> confined by an amorphous insulator.We have instructively ascribed the strong conductionvalence<br /> band coupling found in these systems to a strong mixing of the electronic states<br /> which therefore requires a theoretical model to properly account for its effect. Within the<br /> framework of the k.p effective mass method, we have used an 8x8 Kane Hamiltonianfor<br /> realizing the strong admixture in this central force problem and then we have also<br /> considered sets of symmetries associated with these electronic states and their angular<br /> momenta using orthogonal periodic functions (OPFs). To carry out both analytical and<br /> numerical calculations, two Hilbert space tensorial products for defining an appropriate<br /> new Hilbert space have been attempted for the first time in which the symmetric QD<br /> Hamiltonian may be properly defined and manipulated when applying the k.p effective<br /> mass approximation on the spherical QDs. Following the use of Kane bases, the Hilbert<br /> space has been constructed by OPFs. Apparently our results show that the QD electronhole<br /> energies are dependent on the size of QDs as expected.</p>