Interfacial Modulation Of Organic/Silicon Heteroiunction Solar Cells And Their Integration With Other Energy Harvesting Devices

With the human society developing,energy supply is becoming a key problem which may slow down the speed of development.To exploit and investigate renewable clean energy is a critical project for scientific researchers.Solar cell,which can convert solar energy into electricity,has been widely studied in order to realize low-cost and effective solar energy utilization.Although crystal silicon based solar cell has been successfully commercialized,but the complex fabrication process may limit its development in the future.In order to improve conversion efficiency and decrease fabrication cost,researchers are continuously exploiting new type solar cells witch can be applied in various situation.Under such atmosphere,combining low-cost conjugated conductive polymer suh as Poly(3,4-ethylenedioxythiophene)/poly(styrenesulfonate)(PEDOT:PSS)with crystal silicon to fabricate organic-inorganic heterojunction solar cell has been attracted wide attention.Solar cell based on PEDOT:PSS/N-Si heterojunction promises low fabrication cost and high conversion efficiency.Then,detailed work mechanism of this kind solar cell is still unclear.In order to disclose the machanism,we map the carrier distribution of PEDOT:PSS/N-Si interface by scattering-type near field optical microscope(s-SNOM).Based on the understanding of device working mechanism,we propose a light-induced field effect solar cell structure to improve device performance.At last,we integrate PEDOT:PSS/N-Si heterojunction solar cell with silicon based direct-current triboelectric nanogenerator to realize an all-weather available electric source device.Followings are the main content of this work:1.Carrier distribution of PEDOT:PSS/N-Si heterojunction was mapped by scattering-type near field optical microscope.At the interface,space charge region in silicon side with thickness about 400 nm has been observed,which may form a barrier to stop electrons injecting into PEDOT:PSS.With additional help of scanning Kelvin probe microscope(SKPM),another space charge region in PEDOT:PSS side with thickness between 25 nm and 28 nm has been observed,which may decrease the possibility that electrons tunnel into PEDOT:PSS.Based on the above results,an energy alignment model including two space charge regions has been proposed to explain excellent photovoltage effect of PEDOT:PSS/N-Si heterojunction.2.A light-induced field effect solar cell with conversion efficiency of 14.3%was fabricated by combing perovskite quantum dots with PEDOT:PSS/N-Si heterojunction.Compared to the device without light-induced polarization structure,a 12%enhancement in performance has been achieved.In this solar cell,short wavelength light was used to induce extra electric field to enhance built in potential,which will improve device performance.Through analyzing influence factors related to light-induced polarization electric field,main characters of light-induced polarization materials have been conclude,including large bandgap,charge trapping ability and electric polarization ability.3.A triboelectric nanogenerator with direct current and high current density output was fabricated based on crystal silicon.Integrating this nanogenerator with PEDOT:PSS/N-Si heterojunction solar cell,an all-weather available electric source was successfully fabricated.Solar energy can be converted into electricity by his integrated device while mechanical energy can be converted into electricity without sunlight.(Solar cell performance:11.2%,triboelectric nanogenerator perfonnance:open circuit voltage:0.6 V,short circuit current density:6.7 A/m2)...