Organic Layer And Silicon Nanostructure On Photovoltaic Performance Of Organic-silicon Heterojunction Solar Cells

Utilization of solar energy efficiently has became a favorable solution for the environment pollution and energy shortage and the research on solar cells has drawn more and more attention.Among all kinds of solar cells,the silicon based organicinorganic hybrid solar cells meanwhile combine the advantages of Si with well light absorption and electron transport and organic materials with low cost and simplify fabrication processes.In this thesis,antireflection structure and interface that minimize optical and electrical losses are studied to obtain better device performance.In optical terms,we introduce an inverted pyramid structure by copper ion-assisted etching to reduce the reflection loss of incident light,and we attempt to use highly-transparent poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate)(PEDOT: PSS)to reduce optical parasitic absorption losses.In the terms of electricity,n-type conjugated polymers are used to improve the back-contact quality of the device,then a highly efficient silicon-organic hybrid solar cells are obtained.The main contents of the full text are as follows:Firstly,the basic principles and parameters of solar cells are introduced,and current development and research in silicon-based solar cells are reviewed.Secondly,the structure of silicon inverted pyramid by copper ion-assisted etching is investigated.By studying the different concentrations of copper nitrate and reaction temperature,a more uniform pyramid structure is obtained.At the same time,the addition of additives dramatically improves the reproducibility of the structure.At last,the short-circuit current density of silicon solar cell is dramatically enhanced.Thirdly,the parasitic absorption is reduced in solar cell by a high transmittance PEDOT:PPS(PCE)replacing traditional one PH 1000.As a result,Si/FCE hybrid solar cells with high short-circuit current density are achieved.Fourthly,conjugated polymers N2200 and F-N2200 as rear side modified layers are inserted in device to improve rear side charge transfer.Combining with density functional theory simulation measurement it is found that the shorter distance between organic material and silicon atom is favorable for charge transport and surface passivation.At last,power conversion efficiency of 14.5% in silicon-organic solar cell is achieved.