Use of hexamethyldisiloxane for p-type microcrystalline silicon oxycarbide layers

Abstract

The use of hexamethyldisiloxane (HMDSO) as an oxygen source for the growth of p-type siliconbased layers deposited by Plasma Enhanced Chemical Vapor Deposition is evaluated. The use of this source led to the incorporation of almost equivalent amounts of oxygen and carbon, resulting in microcrystalline silicon oxycarbide thin films. The layers were examined with characterisation techniques including Spectroscopic Ellipsometry, Dark Conductivity, Fourier Transform Infrared Spectroscopy, Secondary Ion Mass Spectrometry and Transmission Electron Microscopy to check material composition and structure. Materials studies show that the refractive indices of the layers can be tuned over the range from 2.5 to 3.85 (measured at 600 nm) and in-plane dark conductivities over the range from 10 −8 S/cm to 1 S/cm, suggesting that these doped layers are suitable for solar cell applications. The p-type layers were tested in single junction amorphous silicon p-i-n type solar cells.

Quasi-fivefold symmetric electron diffraction patterns due to multiple twinning in silicon thin films grown from hexamethyldisiloxane

“…In other words, increasing the flow rate of HMDSO promotes the growth of an amorphous phase. This result is in agreement with the crystalline fraction evaluated from ellipsometric modelling of the films deposited on glass substrates (Goyal et al, 2016). What is more important is that the addition of HMDSO does not induce random microcrystalline growth; the films are a combination of multiply twinned oriented crystalline growth and amorphous growth.…”

“…In other words, a competition between twinned epitaxial and microcrystalline growth modes would be present, depending on to what extent the surface beneath the HMDSO layer is ordered. This is consistent with the fact that our layers are near the amorphous-to-microcrystalline transition when deposited on glass substrates (Goyal et al, 2016). Note that perfect silicon epitaxial growth conditions lead to epitaxy on a monocrystalline wafer and to amorphous deposition on glass substrates (Roca i Cabarrocas et al, 2012).…”

“…for the deposition of the HMDSO layer. More information about the growth conditions is given by Goyal et al (2016).…”

“…We performed secondary ion mass spectrometry (SIMS) profiling on the present samples (Goyal et al, 2016) and recorded elemental maps of silicon, carbon and oxygen. The latter were performed, using EFTEM, on samples deposited with an HMDSO flow rate of 0.45 s.c.c.m.…”

Contested Ground: Network Governance in Australia's Migration Industry

“…Participants' perspectives on the stigmatization of their profession have also been advocated more broadly. The migration industry has collectively attempted to remove the word "agent" from the RMA title, arguing that the term carries negative associations often with undercover activities of spies, smugglers, traffickers, and pimps (McKechnie, 2010;Goyal, 2016).…”