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

• Main Author: , Kamsul Abraha, Muhamad Darwis Umar, and Mirza Satriawan
• Format: Article NonPeerReviewed
• Published: [Yogyakarta] : Fak. MIPA UGM 2007
• Online Access: https://repository.ugm.ac.id/93892/; http://repository.ugm.ac.id/digitasi/index.php?module=cari_hasil_full&idbuku=1687
• Institution: Universitas Gadjah Mada

<p>We present first principles calculations of the electronic structures of spherically<br /> symmetric quantum dots (ODs) in direct-bandgap silicon nanocrystals which are potentially<br /> confined by an amorphous insulator. We have instructively ascribed the strong conductionvalence<br /> band couplingfound in these systems to a strong mixingof 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 ~ssociated 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 OD<br /> Hamiltonian may be properly defined and manipulated when applying the k.p effective<br /> mass approximation on the spherical ODs. Following the use of Kane bases, the Hilbert<br /> space has been constructed by OPFs. Apparently our results show that the OD electronhole<br /> energies are dependent on the size of ODs as expected.</p>