Study On The Third Component And Device Structure Design To Improve The Performance Of Organic Building Photovoltaic

Organic solar cells（OSCs）show great potential for application due to their light weight,solution processability and the possibility of preparing flexible devices.At the same time,the adjustable absorption spectrum facilitates the preparation of semi-transparent organic solar cells（ST-OSCs）.ST-OSCs have a promising application in building materials,automobile windows and greenhouse windows.However,there are problems in semi-transparent organic photovoltaics such as low power conversion efficiency（PCE）and insufficient light utilization（LUE）,which are not conducive to their commercialization.In this paper,a printable biomimetic photonic crystal reflective layer is proposed for use in organic photovoltaic devices to solve the above problem.As a type of photonic crystal,the reflective wavelength of the inverse-opal structure can be controlled by adjusting its particle size to reflect light at wavelengths matching the absorption range of the active layer material,thus enhancing the secondary absorption of light by the active layer film and thereby improving the photovoltaic performance of the device.In addition,we optimized the structure of the active layer in pseudo-planar heterojunction layer（PPHJ）organic solar cells in order to improve the photovoltaic efficiency of organic solar cells,and explored the effect of the position of the third component added on the photovoltaic performance of the devices.The contents of the study are as follows:1.The third component fullerene derivative PC₇₁BM is added to the BTB7-Th:F8IC system to prepare high ST-OSCs by high throughput printed.The transmittance of the OSCs is also adjustable by optical strategy.Inverse-opal photonic crystal is a type of photonic crystal that can reflect light of a fixed wavelength by modulating its particle size without impeding the transmission of light of other wavelengths.Due to this property,we enhance the light absorption of the active layer material in a fixed wavelength range by adjusting its particle size to obtain reflected light that matches the wavelength of the absorption spectrum of the donor/acceptor material in the active layer.At the same time,the Mo O_x,which formed the inverse opal structure,and the outer glass layer provide an increased average visible light transmission of the photovoltaic device.Based on this strategy,the PCE of the ternary organic photovoltaic device with an inverse-opal photonic crystal is 9.93%,the V_OC is0.65 V,J_SC is 23.13 m A/cm²,an FF is 66.60%,AVT is 40.36%and the LUE is 4.01%.2.The third small molecule BTR-Cl is added to the donor or acceptor layers of organic solar cells active layers based on a PPHJ structure to explore whether the addition of the third component,introduced to form a more pronounced vertical phase separation structure,is related to the nature of its electron gain and loss or to its molecular chain length.The results show that the addition of a third component small molecule donor to the donor layer can optimize the morphology of the active layer film in organic photovoltaic devices,forming a more pronounced vertical phase separation structure,while increasing the charge transfer efficiency.The PCE of the PPHJ structured organic solar cell device based on the PM6:BTR-Cl/BTP-e C9 system prepared by the above strategy reached 17.02%,which is higher than the device based on PM6/BTR-Cl:BTP-e C9 system（the PCE is16.46%）.