Black silicon with high density and high aspect ratio nanowhiskers
Journal article, 2011

The physical properties of black silicon (b-Si) formed on Si wafers by reactive ion etching in chlorine plasma are reported in an attempt to clarify the formation mechanism and the origin of the observed optical and electrical phenomena, which are promising for a variety of applications. The b-Si consisting of high density and high aspect ratio sub-micron length whiskers or pillars with tip diameters of well under 3 nm exhibits strong photoluminescence (PL) both in the visible and the infrared, which is interpreted in conjunction with defects, confinement effects and near band-edge emission. Structural analysis indicates that the whiskers are all crystalline and encapsulated by a thin Si oxide layer. The infrared vibrational spectrum of Si-O-Si bondings in terms of transverse-optic (TO) and longitudinal-optic (LO) phonons indicates that disorder induced LO-TO optical mode coupling can be an effective tool in assessing the structural quality of the b-Si. The same phonons are likely coupled to electrons in visible region PL transitions. Field emission properties of these nanoscopic features are demonstrated indicating the influence of the tip shape on the emission. Overall properties are discussed in terms of the surface morphology of the nanowhiskers.

si nanocrystals

luminescence

nanowires

photoluminescence

arrays

solar-cells

temperature

nanostructures

infrared-absorption

field-emission properties

Author

S. Kalem

TUBITAK Marmara Research Center

P. Werner

Max Planck Society

Örjan Arthursson

Chalmers, Microtechnology and Nanoscience (MC2), Nanofabrication Laboratory

V. Talalaev

Max Planck Society

Bengt Nilsson

Chalmers, Microtechnology and Nanoscience (MC2), Nanofabrication Laboratory

Mats Hagberg

Chalmers, Microtechnology and Nanoscience (MC2), Nanofabrication Laboratory

Henrik Frederiksen

Chalmers, Microtechnology and Nanoscience (MC2), Nanofabrication Laboratory

Ulf Södervall

Chalmers, Microtechnology and Nanoscience (MC2), Nanofabrication Laboratory

Nanotechnology

0957-4484 (ISSN) 1361-6528 (eISSN)

Vol. 22 23

Subject Categories

Physical Sciences

DOI

10.1088/0957-4484/22/23/235307

More information

Latest update

2/21/2018