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In this work density of states (DOS) was obtained on boron-doped microcrystalline silicon samples [µc-Si:H (B)] from the thermally stimulated conductivity (TSC) technique and compared with results obtained by the modulated photoconductivity methods. To explain the poor agreement between the DOS obtained from the TSC and the other methods, it is shown by means of numerical simulations that the DOS is very sensitive to experimental errors introduced in the calculation of the µnτn product (mobility of electron x lifetime of the electron). The TSC method is applied here for the first time to calculate the density of defect states in the forbidden band of µc-Si:H samples. [ABSTRACT FROM AUTHOR]

In this work, Boron-doped microcrystalline silicon films were deposited in a plasma-enhanced chemical vapor deposition (PECVD) system. The reaction gas was a mixture of 94% hydrogen and 6% silane (SiH4), adding diborane (B2H6) as a dopant gas in the range of 0-100ppm. The effects of the Boron concentration on the optical properties were investigated through optical transmittance and constant-photocurrent method (CPM) measurements, obtaining the wavelength dependence of the optical constants, the film thickness and the optical gap. The CPM measurements show that the increase of the doping level causes a systematic increase of the absorption coefficient spectra in the low-energy region. The electrical properties were investigated by photo and dark-conductivity measurements. Dark conductivity measurements show that the activation energy increases for B2H6 concentrations up to 25 ppm, then decreasing again for higher Boron contents. [ABSTRACT FROM AUTHOR]