The Study Of Organic-inorganic Hybrid?C₆H₅C₂H₄NH₃?₂Sn_xPb_1-xI₄ And Its Application In Perovskite Solar Cells

The perovskite solar cells have attracted a lot of attention all over the world for their simple preparation process,low costs and high photo-electron conversion efficiency.Organic-inorganic perovskite-like hybrids are applied as light absorption materials in perovskite solar cells and CH₃NH₃PbI₃ is the most studied.Except for CH₃NH₃PbI₃,many other advanced hybrid materials were also applied in perovskite solar cells as light absorbers.The dissertation introduced the layered organic-inorganic perovskite-like hybrids?C₆H₅C₂H₄NH₃?₂Sn_xPb_1-xI₄?x=0,0.3,0.5,0.7,1?,whose powders were synthesized by a hydrothermal method and films prepared by the solution method.Meanwhile,perovskite solar cells based on?C₆H₅C₂H₄NH₃?₂Sn_xPb_1-xI₄ were prepared.The main conclusions of our work are showed as follows:?1??C₆H₅C₂H₄NH₃?₂Sn_xPb_1-xI₄?x=0,0.3,0.5,0.7,1?synthesized by hydrothermal method are a series of layered organic-inorganic perovskite-like hybrids,which grow preferentially orientated along the?00l?orientation and consist the?002l?diffractions.The XRD of hybrid powders indicate that the diffraction peaks will shift to high angles and the interlayer distances will reduce from 16.36nm to16.27nm with the increase of x.Moreover,the PL spectra suggest every hybrid has different photoluminescence peaks and intensity.In addition,the UV-Vis light absorption spectra show that the absorption edge undergoes an obvious red-shift with the increase of x and the wavelength is up to 730nm when x=1.The results indicate that varying x reflecting the ratio of Sn and Pb can tune the light absorption properties and then adjust the band gaps of these hybrids.?2?The films of?C₆H₅C₂H₄NH₃?₂Sn_xPb_1-xI₄?x=0,0.3,0.5,0.7,1?were prepared by solution method and studied the effects of conditions,such as substrates,atmosphere and heat treatment temperatures.The results indicate that the change rule for the UV-Vis light absorption spectra of hybrid films is similar to that of their powders,but the absorption edges of films,whoes maximum absorption edge is 650nm,undergo a blue-shift compared to that of their powders.According to the band gaps of the hybrid films and the results of their UPS spectra,the positions of valence bands for these hybrid films will go up and the positions of conduction bands will descend firstly and then elevate with the increase of x.And the positions of valence bands for the Sn-based hybrid films are higher than that of?C₆H₅C₂H₄NH₃?₂PbI₄ film,while the positions of conduction bands are lower than that of it.The results of chemical stability research show that in atmosphere the hybrids will be stable when x?0.3,while they will be unstable when x?0.5,and especially for x=1 the hybrid can't nearly be existed in atmosphere.?3?The structure of layered organic-inorganic perovskite-like hybrid?C₆H₅C₂H₄NH₃?₂Sn_xPb_1-xI₄?x=0,0.3,0.5,0.7,1?based solar cells is FTO/BL-TiO₂/Meso-TiO₂/Perovskite/spiro-OMeTAD/Au.The results of their photo-electron performance measurements indicate that the PCE of these solar cells will go up and then descend with the increase of x and the PCE is up to the highest when x=0.5.The highest PCE of the solar cell is 1.27%with J_sc 5.18mA/cm²,V_occ 0.703V and FF 35%.