Nanocrystalline silicon prepared at high growth rate using helium dilution

Abstract

Growth and optimization of the nanocrystalline silicon (nc-Si : H) films have been studied by varying the electrical power applied to the helium diluted silane plasma in RF glow discharge. Wide optical gap and conducting intrinsic nanocrystalline silicon network of controlled crystalline volume fraction and oriented crystallographic lattice planes have been obtained at a reasonably high growth rate from helium diluted silane plasma, without using hydrogen. Improving crystallinity in the network comprising ~ 10 nm Si-nanocrystallites and contributing optical gap widening, conductivity ascending and that obtained during simultaneous escalation of the deposition rate, promises significant technological impact.

Influence of helium dilution of silane on microstructure and opto-electrical properties of hydrogenated nanocrystalline silicon (nc-Si:H) thin films deposited by HW-CVD

“…Bhattacharya and Das [33] proposed that with He as a diluent gas, a large amount of energy happens to transfer to the growth zone by the bombardment of ionized He + ions and metastable He* atoms from the plasma. However, it seems that the above assumption is not valid in HW-CVD process since the hot filament source cannot ionize the He because of its high ionization energy (24.6 eV) and the number of excited He atoms is relatively small due to the high excitation energy (19.85 eV).…”

“…Various noble/inert gases like helium (He), argon (Ar), neon (Ne), Krypton (Kr) and xenon (Xe) have been employed in conventional PE-CVD method for SiH 4 dilution to increase the deposition rate. These gases have shown strong influence on the structure and morphology of the films [7,[30][31][32][33][34][35]. So far, the HW-CVD method has not been studied for the synthesis of nc-Si:H films using noble/inert gas dilution of SiH 4 and no reports exist in the literature.…”

Formation of Li10Zn4O9, Li2MoO3, and ZnSeO3 Nanophases: Roles in Electrical Conductivity and Electrochemical Stability in Lithium Ion Conductors and their Crystalline Counterparts

“…Electrical conduction 4,5 of glassy ceramics containing Li 2 O and their crystalline counterparts are anticipated to get their structural information, which can be believed to be key ideas for conduction processes. These energy materials could be thought better to some extent in comparison with other energy materials 6,7 due to their costly preparation methods. Here, a comparison between electrical conduction of Li 2 O doped new glassy ceramics and their crystalline counterparts has been discussed to make it possible to understand the new features of lithium ion conductors.…”