The Application Of Micro-nano Structures In Perovskite Optoelectronic Devices And Their Photophysical Properties

Organic-inorganic hybrid perovskites have been widely used in solar cells and light-emitting diodes due to their direct bandgap materials,adjustable bandgap,large carrier mobility,and large exciton ionization energy.and attention.Although the research on perovskite solar cells(PSCs)and perovskite electroluminescent diodes(Pe LEDs)has made rapid progress,the theoretical maximum efficiency is still not reached.A common problem they face is the reflection caused by the difference in material emissivity,which affects the light absorption of PSCs and the light outcoupling of Pe LEDs,reducing the efficiency of the device.How to improve the inside of the device,overcome the inherent defects based on the device itself,and realize the light regulation inside the device is an urgent problem to be solved at present.Most of the current research focuses on the development of new preparation processes for flat and void-free perovskite thin films,and the research on improving interfacial contact,while there are very few studies on its optical aspects.Therefore,in this paper,the FDTD-Solutions optical simulation software is used to study the propagation characteristics of electromagnetic waves in perovskite optoelectronic devices,and the specific mechanism of electromagnetic wave transmission loss is clarified.Specific guidance is given to improve the transmission efficiency of electromagnetic waves in perovskite solar cells and light-emitting diodes by micro-nano structures,which broadens the application scenarios of micro-nano structures in perovskite optoelectronic devices.The specific research content and research results are divided into the following parts:First,for the application of solar cells in greenhouses,a translucent spectrally selective perovskite solar cell was designed using the FDTD optical simulation software based on the finite difference time domain method.The pyramid-shaped micro-nano structure makes the transmission spectrum match the plant's absorption spectrum,and the quantum efficiency of the solar cell is increased by 5%without affecting the optimal growth state of the plant.Secondly,the light-emitting characteristics of MAPb Br₃-based perovskite light-emitting diodes were simulated by FDTD software,and the effect of the shallow-textured micro-nano structure at the MAPb Br₃/PEDOT:PSS interface on the light-emitting characteristics of the device was discussed.The period of the micro-nano structure is scanned and optimized in a wide range by comparing the far-field data.The results show that the intensity of diffraction interference is the largest after the light passes through the micro-nano structure with a period of 400 nm at the interface,and the effect of light extraction is the best.Finally,the preparation method of micro-nano structure and perovskite light-emitting diodes are explored.The results show that the micro-nano structure can be formed on the surface of the silicon wafer by etching the metal mask formed by the self-aggregation of silver thin film,but its distribution is disordered;Using the metal grid prepared by the self-assembled PS particles as a mask can form micro-nano structures with good periodicity.Afterward,a soft template with a micro-nano structure was prepared by using PFPE inverted mold,which was used as a medium to transfer the micro-nano structure,and finally,a perovskite light-emitting diode device with a 400nm period micro-nano structure was prepared.The EQE was improved from 6.5%of planar devices to 10.3%of textured devices.