Grain boundaries can probably offer location for most of the oxygen impurities out of post-oxidization, where the oxygen atoms can incorporate the dangling bonds along the grain boundaries. On the other hand, the incorporation of oxygen impurities in the films is effectively

influenced by H radicals. The mechanism is that H radicals generated in the plasma during the growth process of the films are accelerated by the RF power and impinge onto the growing surface of the films with a certain kinetic energy. Those H radicals with enough kinetic energy can passivate the dangling bonds along the grain boundaries and effectively prevent the oxygen impurities from post-oxidization. The bonded H located at grain boundaries can form hydrides with a certain type of TGF-beta inhibitor PF477736 bonding configuration, which can be identified from the deconvoluted peaks of the Si-H stretching mode of the peak at 2,090 cm-1 as mentioned in Figure  2a. These hydrides with different types of bonding configurations were then investigated in this part to help us accurately understand the spatial correlation between the hydrogen-related microstructures and oxygen impurities. The spectrum of a representative sample with R H = 98.2% was chosen to be deconvoluted into eight Gaussian absorption peaks as presented in Figure  5a, standing for several types of different bonding configurations. The buy Eltanexor frequency position of the deconvoluted

peaks depends on the unscreened eigen-frequency of the hydride, bulk screening, local hydride density, and possible mutual dipole interactions of the hydrogen incorporation configuration [31]. The low stretching mode (LSM; 1,980 to 2,010 cm-1) originating from the a-Si:H tissue is often in an isolated Si-H form in the bulk. The middle stretching mode (MSM; 2,024 to 2,041 cm-1) due to the Si-H stretching vibrations is located at the platelet-like configuration of the amorphous-crystalline

interface with massive defect states. The high stretching click here mode (HSM; 2,086 to 2,094 cm-1) responsible for Si-H2 at the internal surface of microvoids [32] is also related to a number of unsaturated dangling bonds. The extreme HSM (EHSM; 2,140 to 2,150 cm-1) arises from the trihydrides in the film prepared under high hydrogen dilution conditions. Three narrow HSMs (NHSMs; at 2,097, 2,109, and 2,137 cm-1) represent mono-, di-, and trihydrides, respectively, on the crystalline surface. Lastly, the stretching mode at approximately 2,250 cm-1 corresponds to the hydride O x Si-H y vibration with oxygen atoms back-bonded to the silicon atoms [33]. Figure 5 Deconvoluted Si-H stretching mode and correlation between the integrated intensity of MSM and oxygen content. (a) Typical deconvoluted Si-H stretching mode of the nc-Si:H thin film under R H = 98.2%. The solid curves are the overall fitting results using eight Gaussian peaks.