Abstract
This paper investigates the effect of thickness on the properties of p-type polycrystalline Si thin film deposited onto silver-aluminium back contact-coated polyethylene terephthalate (PET) substrate. In the fabrication, the substrate was coated using screen printing technology, and boric acid (0.1 g/l) was used as the boron-doping source. Three different weights of boron-doped Si powder were dissolved in 40 ml polyethylene glycol to create Si pastes with different viscosities. These pastes were used to print three different thicknesses of p-type Si thin film on Ag-Al alloy-coated PET substrates. Different techniques were employed to analyze the effects of varying thicknesses on the properties of Si thin layers. X-ray diffraction (XRD) was used to determine the crystallite size (D) and stress in the Si thin film. Surface morphology and roughness were studied by scanning electron microscopy (SEM) and atomic force microscopy (AFM). The thin film component elements were detected using EDX attached to an SEM system. The carrier concentration, Hall mobility, and other electrical properties were determined through Hall Effect measurements. The optical band gap was determined from the UV-visible absorbance spectrum, and the results indicate that band gap energy is proportional to the thickness of the Si layer.