Sdudy On The Performance Improvement Of Perovskite Solar Cells By LSPR Effect

The new generation of perovskite materials,represented by methylamine lead iodide,have the optical band gap matched with sunlight,high carrier mobility,long carrier diffusion distance and large optical absorption coefficient,so they are widely used in the field of solar cells.By 2021,the highest photoelectric conversion efficiency(PCE)of small area(?0.01cm²)solar cells(referred to as perovskite solar cells,PSCs)with perovskite materials as light absorbing layer is 25.5%,which brings new opportunities for the development of high efficiency and low-cost photovoltaic devices.In order to improve the utilization of incident light in PSCs by using plasma nanostructures,the local surface plasmon resonance(LSPR)characteristics of PSCs are regulated by synthesizing nanostructures with different morphologies and sizes,and the physical mechanism of LSPR improving the performance of PSCs is elucidated.The main research contents are summarized as follows:1.The LSPR effect of gold nanorods(AuNRs)was used to promote the generation of photogenerated carriers in CsPbBr₃ perovskite quantum dot(QDs)films.AuNRs with different aspect ratios and adjustable LSPR at 550-900nm were synthesized by seed induction method.All inorganic perovskite CsPbBr₃ QDs with uniform size were synthesized by thermal injection method,and AuNRs modified CsPbBr₃ QD films were prepared on silicon substrates by spin coating method.Steady state fluorescence spectroscopy characterization shows that AuNRs can effectively increase the generation of photogenerated carriers in CsPbBr₃ QD films,enhancing their photoluminescence intensity.The main physical reasons are as follows:The LSPR wavelength of AuNRs matches the luminescence peak of CsPbBr₃,which improves the recombination rate of photogenerated carriers in CsPbBr₃,and provides a theoretical basis for the improvement of photoelectric performance of perovskite solar cells by noble metal nanostructures.2.The visible light LSPR effect of gold octahedral nanoparticles(AuNOs)was used to improve the performance of perovskite solar cells.Because AuNRs can improve the utilization of incident light in perovskite films,AuNOs were synthesized by polyol reduction method.By adjusting the p H value of the growth solution,AuNOs with different sizes and adjustable LSPR wave growth range(600-1000nm)were obtained,and the PSCs:FTO/TiO₂/(AuNOs)/perovskite/Spiro-OMeTAD/Au were assembled.The experimental results show that the AuNOs plasma nanostructure at the TiO₂/perovskite interface can effectively scatter the incident light into the perovskite film through resonance scattering,and effectively improve the utilization of the incident light in the perovskite film with the same thickness.Moreover,the broad-band LSPR peak is more conducive to the light capture effect of plasma nanostructures,the enhancement effect is more significant,and more photogenerated carriers are generated.At the same time,the AuNOs between the electron transport layer and the perovskite layer can effectively reduce the surface contact potential of TiO₂ by hot electron injection,improve the electron extraction ability at the interface,and improve the photoelectric performance of the whole device.The best PCE of 19.05% is obtained.This part of the results show that it is feasible to improve the photoelectric performance of PSCs by using LSPR effect of AuNOS,which has important guiding significance to study the application of LSPR effect in PSCs.3.The performance of perovskite solar cells was improved by using the near-infrared LSPR effect of copper telluride nanocrystals(CuTeNCs).CuTeNCs with uniform size and LSPR effect in near infrared region(800-2000nm) were synthesized by thermal injection method.The LSPR effect of semiconductor CuTeNCs is due to the large number of copper vacancies caused by copper deficiency,which leads to the high concentration of free carriers(holes),which makes the nonmetal CuTeNCs exhibit LSPR characteristics.Perovskite devices obtained improved PCE that fabricated by modifying perovskite with CuTeNCs:FTO/TiO₂/perovskite(CuTeNCs)/Spiro-OMeTAD/Au.