The thickness dependence of the electronic and optical properties of a- sige : H films grown by P-CVD technique

الملخص EN

This paper reports the dependence of the electronic and optical properties of hydrogenated amorphous silicon germanium (a-SiGe : H) films grown by plasma chemical vapor deposition (PCVD( technique on film thickness.

The effects of varying the thickness from ~ 0.1 to ~ 0.6 μm on dark conductivity (σd), photoconductivity (σph), optical energy gap (Eopt) and Urbach tail width (Eu( of the band tails of localized states in the band gap of the a-SiGe : H film material were investigated.

The observations show an increase in σd, σph and Eopt and a decrease in Eu , with an increase of the film thickness.

The electronic and optical properties of the a-SiGe : H films were correlating with their structural properties.

The electronic and optical quality of a-SiGe : H films were ascribed to the decrease in the width of the band tail of localized states at the conduction band edge and reduction of the structural disorder in the film network.