Hydrogenated nanocrystalline silicon (nc-Si:H) films were deposited by using 13.56MHz plasma-enhanced chemical vapor deposition at 260°C by means of a silane (SiH4) plasma heavily diluted with hydrogen (H2). The high-quality nc-Si:H film showed an oxygen concentration (CO) of ∼1.5×1017at.∕cm3 and a dark conductivity (σd) of ∼10−6S∕cm, while the Raman crystalline volume fraction (Xc) was over 80%. Top-gate nc-Si:H thin-film transistors employing an optimized ∼100nm nc-Si:H channel layer exhibited a field-effect mobility (μFE) of ∼150cm2∕Vs, a threshold voltage (VT) of ∼2V, a subthreshold slope (S) of ∼0.25V∕dec, and an ON∕OFF current ratio of ∼106.

The authors report ultrahigh mobility nanocrystalline silicon thin-film transistors directly deposited by radio-frequency plasma enhanced chemical vapor deposition at 150°C. The transistors show maximum effective field effect mobilities of 450cm2∕Vs for electrons and 100cm2∕Vs for holes at room temperature. The authors argue that the key factor in their results is the reduction of the oxygen content, which acts as an accidental donor.

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Nitrogen-rich amorphous silicon nitride (a-SiNx:H) films with [N]/[Si] ratios ranging from 1.4 to 1.7 were deposited by a 13.56 MHz plasma-enhanced chemical vapor deposition method at a temperature of 120 °C. The films’ composition, dielectric constant, electrical resistivity, and breakdown voltage were evaluated. The electrical properties of a-SiNx:H films with a [N]/[Si] ratio of more than 1.6 are superior to their lower N-content counterparts. Amorphous silicon thin film transistors (TFTs) that incorporate a-SiNx:H dielectrics were fabricated on glass and plastic substrates at a maximum processing temperature of 120 °C. The TFTs exhibit effective field effect mobility of 0.5–0.8 cm2/V s, an ON current of ∼10−5 A, an ON/OFF ratio of more than 106 and a subthreshold slope of 0.5 V/dec. The performance of the transistors seems to be compatible with application of them in active–matrix organic light emitting displays.

This article reports on the structural, electronic, and optical properties of boron-doped hydrogenated nanocrystalline silicon (nc-Si: H) thin films. The films were deposited by plasma-enhanced chemical vapour deposition (PECVD) at a substrate temperature of 150 degrees C. Crystalline volume fraction and dark conductivity of the films were determined as a function of trimethylboron-to-silane flow ratio. Optical constants of doped and undoped nc-Si: H were obtained from transmission and reflection spectra. By employing p(+) nc-Si: H as a window layer combined with a p' a-SiC buffer layer, aSi: H-based p-p'-i-n solar cells on ZnO:Al-coated glass substrates were fabricated. Device characteristics were obtained from current-voltage and spectral-response measurements.