Interface-layer formation mechanism ina−Si:Hthin-film growth studied by real-time spectroscopic ellipsometry and infrared spectroscopy

Electronic states in a-Si:H/c-Si heterostructures

“…While structural properties and the growth mechanism of thin a-Si:H films have been investigated recently, e.g. [1], and a wealth of data on the distribution of gap states is available for thick (>100 nm) a-Si:H films, little is known about the electrical properties of thin films and their interfaces. For such thin films, the present work shows results concerning the distribution of occupied a-Si:H gap and a-Si:H/c-Si interface states, the interface recombination properties and the correlation of these parameters with preparation conditions.…”

Hydrogen bonding in hydrogenated amorphous silicon thin films prepared at different precursor gas temperatures with undiluted silane

“…The band at 2080 cm 1 is attributed to SiH stretching mode at the surfaces [19] or to the presence of the SiH bonds on the inner surface of microvoids [20], and the decrease in the intensity of the band indicates the reduction of the microvoids in the films. As shown in Figure 3, an interesting feature of the IR spectra is the absence of the 2090 cm 1 absorption mode due to the isolated SiH 2 in the bulk [21,22] over all range of gas temperature studied. It is suggested that the monohydride hydrogen bonding configuration is predominant in the a-Si:H thin films deposited at gas temperature of 433 K.…”

Ellipsometry characterization of a-Si:H layers for thin-film solar cells

“…In contrast, the light absorption in the IR region is quite small and the whole a-Si:H layer is evaluated in the IR analysis. It has been reported that C SiH2 is significantly higher at a-Si:H/substrate interface regions due to the a-Si:H island growth on foreign substrates [11]. Accordingly, the slightly higher C SiH2 obtained from the IR analysis is likely caused by the formation of the SiH 2 -interface layer that can not be detected in the near-surface analysis using the visible/UV region.…”