INVESTIGATION OF Si WIRE TRANSMISSION
|Igor P. Ostrovskii 1, Anatoly A. Druzhinin 1, Alla I. Klimovskaya 2, Evgenij G. Gule 2|
1. Lviv Polytechnic National University, 12 Bandera, Lviv 79013, Ukraine
Si wires are prospective for size effect studies. Recently we have found the row of size effects in the wires. Among them there is decrease of lattice parameter in submicron Si wires as comparison with lattice parameter of silicon bulk. In addition visible light photoluminescence is observed in such structures similar with luminescence of porous silicon. Such peculiarities of the wires were explained by peculiarities of their structure. The investigation of crystal structure showed that the wires are heterostructures consisted of Si strained core and porous Si envelope.
In the present paper we study transmission spectra of Si wire array prepared on Si substrate.
The growth method consists in regular deposition of Au dots on Si substrate. Then Si substrate is loaded in a reactor of open vapour-transport system. Thermoprocessing of the reactor at 1100K provides the wires growth from Si-Au droplets according to VLS mechanism. The results of investigation of Si wire structure in AFM have shown that thickness of envelope is of about 5-20 nm depending on the wire diameter (500-5000 nm).
Transmission spectra of wires were measured by use of He-Ne laser with 632,8 nm light-wave length. The prominent performance of the spectra is their strong angle dependence, which we detect using goniometer system. The angle dependence of transmission would be explained by light diffraction on transversive dimensions of the wires. But we have performed the investigation using IR source of light and obtained the same angle figures. Therefore, the revealed peculiarities of transmission are connected with other reason.
Nanosilicon is known to be a crystal with strong birefringence. One can suppose that porous envelope of Si wires is corresponding for angle dependence of light transmission due to appearance of light birefringence. The peculiarities of angle figures depending on the wires geomentry are discussed.
Presentation: poster at E-MRS Fall Meeting 2005, Symposium F, by Igor P. Ostrovskii
See On-line Journal of E-MRS Fall Meeting 2005
Submitted: 2005-06-01 10:52 Revised: 2009-06-07 00:44