Dear Samaneh,

YOUR question is VERY BAD FORMULTED. WHY??

Before we (answerers) answer with knowledge and BRAIN , please give more Infos about your question:

- UV spectra of silicon? Do you mean UV-vis spectrum or spectra (plural) and what a kind of SLICON?

- Are you using dots?

For dots see please this link:

Using UV-vis for the detection and characterization of silicon quantum dots

- Please give details about your spectrometer and VERY IMPORTANT hte kind of compound ( not your investigated compound if it is still secret prior to publication)

- Concerning the change in your UV-spectra, please formulate your question again like in the pdf (see nextlink)

http://www.us.edu.pl/uniwersytet/jednostki/wydzialy/chemia/acta/ac15/zrodla/08_AC15.pdf

here is the pdf title:

CHANGES IN THE UV ABSORPTION OF SILICA

CONTAINING ALIPHATIC MOIETIES

AFTER THERMAL MODIFICATION,

AND THE QUANTITATIVE RELATIONSHIP

BETWEEN THE CHANGES AND THE ORGANIC

GROUP CONTENT

The word CONTAINING (in this title) is important because it describes the kind of compound.

here the first link about silicon quantum dots.

http://cnx.org/content/m34655/latest/?collection=col10699/latest

JRG

Mr Jean

The UV-vis spectra of silicon wafer (type-p)

Thank you