Recombination mechanisms in hydrogenated silicon nanocrystalline thin films

Authors

ZAKI M. SALEH
SALAM M. KMAIL
SAMAH F. ASSAF
ATIF F. QASRAWI

DOI

10.3906/fiz-1301-12

Abstract

The photoconductivity dependences on temperature and illumination intensity were investigated for thin films of hydrogenated nanocrystalline silicon (nc-Si:H) grown by very-high-frequency, plasma-enhanced chemical vapor deposition. The nanocrystalline phase was achieved by heavy hydrogen dilution of silane (SiH_4). We find that the activation energy of the photoconductivity is sensitive to the incident illumination intensity for illumination intensities below 6 mW/cm^2. The photocurrent follows a power-law dependence on illumination intensity (I_{ph}\propto F^{gamma}), with gamma ranging from 0.36 to 0.83. The illumination dependence of the photocurrent suggests 2 different recombination mechanisms depending on temperature. In the lower temperature regime (300-340 K), recombination appears to be dominated by a linear (monomolecular) process, while at higher temperatures (350-400 K), it is likely dominated by a sublinear (bimolecular) process.

Keywords

Photoconductivity, photovoltaics, nanocrystalline silicon, recombination

First Page

283

Last Page

288

Recommended Citation

SALEH, ZAKI M.; KMAIL, SALAM M.; ASSAF, SAMAH F.; and QASRAWI, ATIF F. (2013) "Recombination mechanisms in hydrogenated silicon nanocrystalline thin films," Turkish Journal of Physics: Vol. 37: No. 3, Article 2. https://doi.org/10.3906/fiz-1301-12
Available at: https://journals.tubitak.gov.tr/physics/vol37/iss3/2