Sturctural disorder and silanol groups content in amorphous SiO2

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Abstract

We present a study on the features of the Urbach edge in amorphous silicon dioxide a-SiO2 . The effects of temperature on the absorption edge in the range from 4 to 300 K were studied in both materials having negligible dry, 1017 cm−3 and significant wet, 1019 cm−3 silanol groups contents. Remarkable differences in the values and in the temperature dependence of the Urbach energy in the dry and wet samples were observed. These differences are interpreted as a consequence of a drastic reduction in the degree of disorder in wet materials, which turn out to be characterized by an electronic structure more similar to that of crystalline quartz. Furthermore, our results indicate that silanol groups affect the thermal component of disorder, modifying the vibrational modes of the network.
Lingua originaleEnglish
pagine (da-a)085204-1-085204-7
Numero di pagine7
RivistaPHYSICAL REVIEW. B, CONDENSED MATTER AND MATERIALS PHYSICS
Volume79
Stato di pubblicazionePublished - 2009

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disorders
Amorphous silicon
Silicon Dioxide
amorphous silicon
Electronic structure
vibration mode
Silica
silicon dioxide
electronic structure
temperature dependence
Temperature
silanol
energy
Hot Temperature

All Science Journal Classification (ASJC) codes

  • Condensed Matter Physics
  • Electronic, Optical and Magnetic Materials

Cita questo

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title = "Sturctural disorder and silanol groups content in amorphous SiO2",
abstract = "We present a study on the features of the Urbach edge in amorphous silicon dioxide a-SiO2 . The effects of temperature on the absorption edge in the range from 4 to 300 K were studied in both materials having negligible dry, 1017 cm−3 and significant wet, 1019 cm−3 silanol groups contents. Remarkable differences in the values and in the temperature dependence of the Urbach energy in the dry and wet samples were observed. These differences are interpreted as a consequence of a drastic reduction in the degree of disorder in wet materials, which turn out to be characterized by an electronic structure more similar to that of crystalline quartz. Furthermore, our results indicate that silanol groups affect the thermal component of disorder, modifying the vibrational modes of the network.",
keywords = "Vacuum UV absorption, amorphous silicon dioxide, absorption edge, structural disorder",
author = "Roberto Boscaino and Eleonora Vella",
year = "2009",
language = "English",
volume = "79",
pages = "085204--1--085204--7",
journal = "Physical Review B - Condensed Matter and Materials Physics",
issn = "1098-0121",
publisher = "American Physical Society",

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TY - JOUR

T1 - Sturctural disorder and silanol groups content in amorphous SiO2

AU - Boscaino, Roberto

AU - Vella, Eleonora

PY - 2009

Y1 - 2009

N2 - We present a study on the features of the Urbach edge in amorphous silicon dioxide a-SiO2 . The effects of temperature on the absorption edge in the range from 4 to 300 K were studied in both materials having negligible dry, 1017 cm−3 and significant wet, 1019 cm−3 silanol groups contents. Remarkable differences in the values and in the temperature dependence of the Urbach energy in the dry and wet samples were observed. These differences are interpreted as a consequence of a drastic reduction in the degree of disorder in wet materials, which turn out to be characterized by an electronic structure more similar to that of crystalline quartz. Furthermore, our results indicate that silanol groups affect the thermal component of disorder, modifying the vibrational modes of the network.

AB - We present a study on the features of the Urbach edge in amorphous silicon dioxide a-SiO2 . The effects of temperature on the absorption edge in the range from 4 to 300 K were studied in both materials having negligible dry, 1017 cm−3 and significant wet, 1019 cm−3 silanol groups contents. Remarkable differences in the values and in the temperature dependence of the Urbach energy in the dry and wet samples were observed. These differences are interpreted as a consequence of a drastic reduction in the degree of disorder in wet materials, which turn out to be characterized by an electronic structure more similar to that of crystalline quartz. Furthermore, our results indicate that silanol groups affect the thermal component of disorder, modifying the vibrational modes of the network.

KW - Vacuum UV absorption, amorphous silicon dioxide, absorption edge, structural disorder

UR - http://hdl.handle.net/10447/38694

M3 - Article

VL - 79

SP - 085204-1-085204-7

JO - Physical Review B - Condensed Matter and Materials Physics

JF - Physical Review B - Condensed Matter and Materials Physics

SN - 1098-0121

ER -