| Along with the rapid development of economy and technology,and the change of people's lifestyle,the traditional energy structure has been unable to meet the growing needs of human's urgent demand for energy.It has become the inevitable choice to develop a renewable clean energy for the sustainable development of human society.Because of its environmentally friendly characteristic,solar cells as a good choice to solve the energy shortage problem has been a research foucs in the world since 1980 s.However,the disadvantages of high cost,complex process fot the inorganic solar cells and low efficiency,poor stability for the organic solar cells restrict the further development and popularization of photovoltaic devices.Organic inorganic hybrid solar cells,especially composted of poly(ethylene oxygen two 3,4-thiophene): poly(styrene sulfonate)(PEDOT:PSS)and N type silicon,has been paid much attention for the researchers from all over the world in recent years,which have combined the advantages of inorganic solar cells and organic solar.PEDOT:PSS compsted of by conductive polymer poly(3,4-ethylene dioxythiophene)(PEDOT)and poly(styrene sulfonate)(PSS)is quite promising as a next-generation transparent material for solar cell.PEDOT:PSS films have high transparency in the visible range,high mechanical flexibility,excellent thermal stability and can be fabricated through conventional solution processing.However,PEDOT:PSS consists of hydrophobic conductive PEDOT and hydrophilic insulating PSS chains via ionic chemical bonds.Its structural and electrical inhomogeneity caused by the insulating PSS component shows a poor conductivity.Therefore,more efforts should be put forward to improve the conductivity of PEDOT:PSS,which is the main issue weakening the charge collection capability and a low photovoltaic properties.In this work,we have added a serious of polar solvents,graphene into PEDOT:PSS,in order to develop a beneficial and economical process for improving the performance of c-Si/PEDOT:PSS Hybrid Solar Cells(HSCs).The main contents and result are listed below:1.The properties of PEDOT:PSS thin films with EG solution and this impacts on the performance of the resultant Si-organic HSCs have been systematically investigated.As a result,the HSCs have been fabricated with a PCE of 9.35%,a Jsc of 27.28mAcm-2,a Voc of 558 mV and a FF of 0.609 when 7wt% EG was added into PEDOT:PSS,which is much better than that of no EG addition.The Raman spectroscopy,sheet resistance provided the evidence of the rearrangement of the PEDOT chains,from the coil-like benzoid structure to a more linear or extended quinoid structure,which can improve carrier mobility of the thin films.Besides,the addition of EG solvent has impact on the thickness and transmittance of the PEDOT:PSS thin films.Finally,the fabricated HSCs with 7wt% EG addition iin series lighted a red LED under standard light,showing prospective practical application.2.The properties of PEDOT:PSS thin films with reduced graphene oxide(rGO)addition and their impacts on the performances of the resultant Si-organic HSCs have been systematically investigated.The electrical conductivity of PEDOT:PSS thin film has been improved 35% when rGO was added to PEDOT:PSS,and the fabricated HSCs with 2 mg/ml rGO addition yielded an PCE of 11.95 % with a Jsc of 31.94 mAcm-2,a Voc of 579 mV and a FF of 0.648.The Raman spectroscopy,sheet resistance and EQE analyses suggested that the ?-? interaction between the conductive rGO flakes and the aromatic PEDOT most probably not only provide additional charge transport pathways in hole transport layer to improve carrier mobility,but also suppress the electron recombination at the junction interface.In addition,the rGO serve as an antireflection coating to reduce the reflectance of PEDOT:PSS thin film leading to further enhanced performances of solar cells.However,excess rGO would deteriorate the solar cells performances and it might create additional defects and prevent carriers being collected. |
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