Synthesis Of Crystalline Silicon Film And Their Application In Solar Cells And SERS

In the past several years, improving the photoelectric conversion efficiency of monocrystalline silicon thin-film solar cells, reducing costs and improving the preparation area to make solar cells more efficiently used in the human’s life, are the purposes of the scientists.This paper used wet etching, thin film deposition, annealing, and film transfer techniques to fabricate the nano-porous silicon anti-reflection coating and flexible crystalline silicon thin film solar cell to improve the photoelectric conversion efficiency of the solar cell. In this paper, the finite-difference time-domain method (FDTD) was applied in calculated the electromagnetic field distribution, reflection and absorption of solar cells.1. We reported here an electrode metal-assisted electrochemical etching (MacEtch) process as light management surface-texturing technique for single crystalline Si photovoltaics. Random silver nanostructures were formed on the top of the flat Si surface, micro-and nano-structured surface texturing of Si were carried out based on MacEtch process. Significant reflection reduction was obtained from the fabricated Si sample, with-2%reflection over a wide spectra range (300to1050nm). The work demonstrated the potential of MacEtch process for the fabrication of large area, high efficiency, and low cost thin film solar cell. At the same time, we found the polymer materials have many excellent properties, such as strong acid and alkali resistance, hydrophobicity, and high transmission for the visible light, the flexible POLYMER anti-reflection film was fabricated on the solar cells. This film can enhance the efficiency of the solar cells and protect the solar cells from the environmental erosion.2. In this paper, we reported here experimental demonstration of crystalline semiconductor Si nano-membrane thin film solar cells based on low temperature FAMT transfer process. Low-temperature compatible annealing processes have been investigated for optimal metal contact formation. For2.2micrometer thick p-i junction silicon solar cells on rigid glass substrate, we obtained power efficiency of1.64%, without any anti-reflection coating or light trapping schemes. And for1.7micrometer thick p-i junction flexible silicon solar cells on PDMS substrate, we obtained power efficiency of1.12%with back reflector and0.76%without back reflector for solar cells on flexible PDMS substrate. For the InP materials, we obtained the power efficiency of1%with the thickness of1μm.3. The Raman signal of pyridine was significantly enhanced when the pyridine molecules adsorbed onto rough silver electrode surface, which was found by Fleischmann et al, in1977. With the development of nanotechnology, nano structure is applied to the SERS substrate. In order to investigate the sensitivity and uniformity of Raman spectrum, a non-lithography wet etching method and vacuum deposition method were first used to fabricate the gold-coated silicon pyramidal SERS substrates. The results showed that the uniform SERS enhancement factor (EF) over the entire device surface was measured as3.8X105when the gold film thickness was125nm with R6G (10-7M) as the target analyte. Based on the line-shaped distribution of electric field enhancement, the uniform SERS EF attributed to localized surface plasmon resonance was confirmed by3D finite difference time-domain calculation.