Structure Optimization Of Perovskite Nanocrystals Luminescent Solar Concentrator

Perovskite nanocrystalline thin-film luminescent solar concentrator(LSC),as a potential application in the field of integrated photovoltaic for urban buildings,has attracted wide attention due to its high quantum yield,adjustable perovskite material with band gap and simple preparation technology.However,due to the surface escape cone loss and the low absorption intensity and light collection efficiency of luminous films,the development of LSCS is hindered.Distributed Bragg reflector(DBR)is an excellent wavelength selective filter with an optical stopband that can effectively reduce the surface escape cone loss of LSC.However,the reflection sidelobes of DBR in the nanocrystals absorption band can lead to significant absorption loss,and due to the small Stokes shift of perovskite nanocrystals,The DBR inhibits the surface fluorescence leakage,and at the same time prevents part of the incident light that can be absorbed from entering the fluorescence layer,which further reduces the absorption of the fluorescence layer.Therefore,we design an optical collector combining the top etched anti-reflection grating DBR and silver nanowires(Ag NW)array,build a simulation model based on the finite-difference time-domain method,define reasonable performance characterization parameters,and optimize the structure through numerical simulation calculation.The proposed composite structure effectively suppress the fluorescent surface escape cone loss.The absorption of fluorescence layer is enhanced significantly,and the transmittance of the device meets the application prospect of light collector in photovoltaic window field.The main work is as follows:(1)Combined with the working mechanism of LSC and the corresponding experimental performance characterization principle,a feasible simulation model is built.According to the results of numerical calculation,the thinking of simulation analysis are proposed,and the simulation evaluation parameters of LSC optical performance are given.(2)DBR is introduced on the surface of LSC structure,and its optical stopband is used to reduce the fluorescent surface escape cone loss of the device.A one-dimensional triangular grating is etched on the top of DBR,and the influences of grating period,filling ratio and etching depth on its optical properties are investigated,and the grating structure parameters are optimized.The introduced grating can effectively inhibit the reflection sidelobes of DBR,and the waveguide resonance can compensate the negative effect of DBR on the absorption of nanocrystals to a certain extent,and further enhance the absorption and light collection efficiency of LSC fluorescence layer.(3)Ag NW array is introduced on the lower surface of LSC fluorescence layer to explore the influence of Ag NW with different distribution period and radius on the optical properties of LSC;An LSC consisting of an optimized top etched grating DBR and an Ag NW array is designed.The influence of the radius of Ag NW on the optical properties of the corresponding LSC is investigated,and the mechanism of enhanced absorption is further analyzed in combination with the electric field.The scattering effect of Ag NW array lengthens the optical path of incident light in the fluorescence layer,and forms a generalized Fabry-Perot microcavity with the etched grating DBR at the top of the fluorescence layer.The resulting microcavity resonance enhances the local electric field of the fluorescence layer,and further improves the fluorescence absorption intensity.Ag NW array distributed in a certain period has excellent translucency property,which makes LSC still have good transmittance and can be used in the field of photovoltaic Windows.