The Effect of Power Density on the Surface Layer of Amorphous Thin Film

Abstract

The development of amorphous silicon (a-Si) device technology since the advent of the first solar cell in 1974 has been truly spectacular with commercial products such as photocopiers, laser printers, facsimile machines, liquid crystal display televisions and solar cells now utilizing a-Si. Solar cells are designed to convert at least a portion of available light into electrical energy. Amorphous silicon (a-Si) is the non-crystalline form of silicon. The purpose of this project is to fabricate an amorphous silicon thin film with different values of power density of 10W, 15W, 20W and 25W. A part of the samples is checked using Atomic Force Microscopy (AFM) to check the characteristic of the samples and to verify the sample surface roughness. Besides that, the others samples are also checked with X-Ray Diffraction (XRD). The purpose of this procedure is to check the crystalline level of amorphous silicon. The samples that used are n-type substrate, p-type substrate and corning glass #7059. From the results, it is found that the best sample which has the potential to be amorphous silicon is corning glass. This is because the corning glass samples were showed the theoretical result which is when mean grain size increased, the RMS values decreased. The best parameters to produce amorphous silicon are at power density of 15 to 20 Watt. It is because this sample showed a smooth surface as compared to other samples. The lowest RMS value indicates a smooth surface due to the ability of electron mobility on the surface.