Control of optical bandgap energy and optical absorption coefficient by geometric parameters in sub-10 nm silicon-nanodisc array structure
Authors:
- Weiguo HuWHWeiguo Hu
- Makoto IgarashiMIMakoto Igarashi
- Rikako TsukamotoRTRikako Tsukamoto
- Taiga IsodaTITaiga Isoda
- Kohei M ItohKIKohei M Itoh
- Ichiro YamashitaIYIchiro Yamashita
- Akihiro MurayamaAMAkihiro Murayama
- Yoshitaka OkadaYOYoshitaka Okada
- Seiji SamukawaSSSeiji Samukawa
- 17 January 2012
- journal article
- Published by IOP Publishing in Nanotechnology
- Vol. 23 (6) , 065302
Abstract
A sub-10 nm, high-density, periodic silicon-nanodisc (Si-ND) array has been fabricated using a new top-down process, which involves a 2D array bio-template etching mask made of Listeria-Dps with a 4.5 nm diameter iron oxide core and damage-free neutral-beam etching (Si-ND diameter: 6.4 nm). An Si-ND array with an SiO(2) matrix demonstrated more controllable optical bandgap energy due to the fine tunability of the Si-ND thickness and diameter. Unlike the case of shrinking Si-ND thickness, the case of shrinking Si-ND diameter simultaneously increased the optical absorption coefficient and the optical bandgap energy. The optical absorption coefficient became higher due to the decrease in the center-to-center distance of NDs to enhance wavefunction coupling. This means that our 6 nm diameter Si-ND structure can satisfy the strict requirements of optical bandgap energy control and high absorption coefficient for achieving realistic Si quantum dot solar cells.Keywords
This publication has 25 references indexed in Scilit:
- Towards the intermediate bandNature Photonics, 2011
- Air-Stable Operation of Transparent, Colloidal Quantum Dot Based LEDs with a Unipolar Device ArchitectureNano Letters, 2009
- Lithographic alignment to site-controlled quantum dots for device integrationApplied Physics Letters, 2008
- Quantum Dot Solar Cells. Tuning Photoresponse through Size and Shape Control of CdSe−TiO2 ArchitectureJournal of the American Chemical Society, 2008
- Three-dimensional confinement effects in semiconducting zinc selenide quantum dots deposited in thin-film formMaterials Chemistry and Physics, 2005
- Spin-Polarized Light-Emitting Diodes with Mn-Doped InAs Quantum Dot Nanomagnets as a Spin AlignerNano Letters, 2004
- Cadmium Selenide Quantum Wires and the Transition from 3D to 2D ConfinementJournal of the American Chemical Society, 2003
- Close-to-ideal device characteristics of high-power InGaAs/GaAs quantum dot lasersApplied Physics Letters, 2001
- Silicon single-electron quantum-dot transistor switch operating at room temperatureApplied Physics Letters, 1998
- Quantum mechanical effects in the silicon quantum dot in a single-electron transistorApplied Physics Letters, 1997