Calculation Model for Valence Electrons and Hydrogen Concentration in a‐Si:H

Abstract

A simple model is developped to relate the valence electron number t o the dispersion energy Ed and the static dielectric constant ~( 0 ) .This model is applied to hydrogenated amorphous silicon films prepared by glow discharge decomposition of silane. It is shown that the variation of valence electron number and anion valency explain the variation of the dispersion energy. This model allows to determine the hydrogen concentration in a-Si : H films from two spectroscopic parameters E d and e(0). Ein einfaches Modell wird entwickelt, um die Valenzelektronenzahl mit der Dispersionsenergie E d und der statischen Dielektrizitttskonstante ~( 0 ) zu verknupfen. Dieses Modell wird auf hydrogenisierte amorphe Siliziumschichten angewqndet, die durch Glimmentladungsabbau von Silan hergestellt werden. Es wird gezeigt, da13 die Anderung der Valenzelektronenanzahl und der Anionenvalenz die Anderung der Dispersionsenergie erklaren. Diesea Modell erlaubt, die Wasserstoffkonzentration in a-Si: H-Schichten aus zwei spektroskopischen Parametern, Ed und E(O), zu bestimmen.

Departure of Hydrogen from a-Si:H

“…An analysis of the model used here has been published recently [6]. Here, we recall only the main result.…”

“…Recently [6], we proposed a model to determine the hydrogen concentration C[H] from a knowledge of two spectroscopic parameters deduced from optical measurements. This model was also tested for the case of a-Si: H films produced by glow discharge.…”

Amorphous silicon-carbon films prepared by reactive evaporation

“…In a-Si:H the optical gap depends mainly on the hydrogen content which saturates dangling bonds with a reduction of the gap density of states, related to these defects, and with a widening of the optical gap [21][22][23]. In a-Sil-~Cx :H the optical gap shows a large variation in the whole range of the composition parameter x [1,24].…”

Tristate electrochemical metallization memory based in the hydrogenated nanocrystalline silicon films

“…A broad peak around 640 cm À1 is due to Si-H rocking/waging. 17,18 Fig. 2 shows a TEM and HRTEM image of the nc-Si:H thin films deposited at RF power of 40 W. It can be observed that there are clear and sharp interfaces in Fig.…”