Assembly Of Organic Molecular Containing Conjugate Groups On Monocrystalline Silicon And Photoelectric Properties After Assemblies

Due to its good electrical properties, high purity of monocrystalline silicon is not only the basic material for modern information industry, but also the most common material for photovoltaic battery. Concerning the existing conditions, monocrystalline silicon is the ideal material to produce solar battery for a good battery performance. Therefore, one of the most urgent problems in the study of single crystal silicon solar battery is how to improve the efficiency of photoelectric transformation effectively.In this thesis, we mainly used the organic molecules containing conjugate groups to modify the surface of monocrystalline silicon, and prepared a series of organic conjugated system/n-type monocrystalline silicon composite materials in order to improve the efficiency of photoelectric conversion. All tasks as follow:1. Studies on photoelectric chemical properties of a series of sulfonated polyanilines/n-Si(111) crystalline:Surfaces of Si(111)-H crystal were respectively derived with 4-bromoaniline,4-vinylaniline and 4-ethynylaniline by Grignard reaction and hydrosilylation reactions to give Si-C linked with self-assembled monolayers (SAMs) in the presence of lauroyl peroxide. Assemblies of polyaniline/n-Si(111) crystal were prepared basing on the reactions between SAMs and anilines. Additionally, the sulfonic acid ring-substituted polyanilines (SPANI) were prepared via the above linker molecules to fabricate a series of assemblies of SPANI/n-Si(111) crystal. Analysis results indicated that the open circuit photovoltages of the composite electrodes moved to more negative direction and much large photocurrent densities obtained after -SO32- groups were introduced into the assemblies. Due to the conjugated structure in PANI, the photocurrent density of the composite electrodes that PANI connected to n-Si(111) crystal directly is larger than that of PANI connected to silicon surface by -C=C- bonds, and the latter is larger than that of PANI connected to silicon surface by -C-C- bonds because of conjugated structure existing in assembly of Si-C=C-PANI electrode.2. Studies on photoelectric chemical properties of chlorophyll copper sodium (and its derivatives)/n-Si(111) crystalline:The chlorophyll copper sodium containing C≡C bonds (SCCa) was prepared through replacing terminal C=C bonds in chlorophyll copper sodium (SCC) with C=C bonds and the assemblies of SCC/n-Si(111) and SCCan-Si(111) crystal were fabricated through grafting SCC and SCCa on surface of n-Si(111) by hydrosilylation reactions, respectively. The resulting assemblies presented the structures with porphyrin rings contained in SCC and SCCa linking to n-Si(111) through C-C and C=C bonds, respectively. Analysis results indicated that the photocurrent density of the composite electrodes that SCCa connected to n-Si(111) crystal is larger than that of SCC connected to silicon surface due to conjugated bonds existing between silicon and porphyrin rings.