Effect Of AuAg Alloyed Nanoprisms On The Performance Of Two-dimensional Perovskite Solar Cell And Photodetectors

Organic-inorganic hybrid perovskite materials have become the star materials in the field of optoelectronics due to their excellent optoelectric properties and low production cost,which have wide applications in the fields of in solar cells,photodetectors,etc.The instability of traditional three-dimensional perovskite materials limits their applications.In contrast,two-dimensional?2D?layered perovskites exhibt much improved stabilities due to the introduction of hydrophobic cations which can be regarded as a nanoscale encapsulation of the traditional"perovskite layer".In this thesis,the?PEA?₂?MA?₂Pb₃I₁₀ based two-dimensional layered perovskite solar cells were successfully fabricated and investigated.However,the power conversion efficiency?PCE?of the 2D perovskite solar cells was low?about3.40%?.Studies have shown that the metal nanoparticles incorporated in three-dimensional perovskite solar cellss and organic solar cells can improve the PCE by increasing light absorption and exciton dissociation rates.Here,we have incorporated a silica-coated AuAg alloyed Nanoprisms?AuAgNPrisms@SiO₂?into the 2D layered perovskite solar cells for the first time.The AuAgNPrisms@SiO₂ incorporated devices exhibit 34.1%increase in PCE and32.8%increase in the J_sc with respect to the control devices.Experimental results show that the incorporation of AuAgNPrisms@SiO₂ not only increases light absorption in the active layer but also improves the exciton dissociation at the interfacebetween?PEA?₂?MA?₂Pb₃I₁₀andPC₆₁BM.Inaddition,AuAgNPrisms@SiO₂ can also improve the crysallinity of the?PEA?₂?MA?₂Pb₃I₁₀perovskite film.Moreover,our fabricated AuAgNPrisms@SiO₂ incorporated the2D layered perovskite solar cells are more stable than three-dimensional counterparts and the unencapsulated device degraded to about 50%of its original value after exposure in air ambient for 288 h?12 days?under 52%relative humidity.Next,the AuAg NPrisms@SiO₂ is incorporated into a 2D perovskite photodetectors.The AuAgNPrism@SiO₂ incorporated 2D perovskite photodetectors exhibti a high EQE of 14974.2%at a low driving voltage of-0.3V.R and D^*reach 60.8 A/W and 2×10¹⁴ Jones under 505 nm LED illumination with intensities of 1.8 nW and detection with the low light.By incorporating AuAgNPrism@SiO₂ at the interface between the hole transporting layer and the2D perovskite active layer,EQE,R and D*increased over the wavelength range between 300 nm to 750 nm.The improvement is attributed to the absorption enhancement in the 2D perovskite layer,faster exciton dissociation rate and reduced charge recombination at the interface due to the incorporated AuAgNPrism@SiO₂.This work demonstates a way to improve the performance of 2D perovskite PDs and PSC.