Study On Properties Of Carbazole-based Supramolecular Polymers

In this paper,we designed and synthesized three N-phenylcarbazole-1,3,5-benzenetricarboxamide derivatives,and studied their supramolecular self-assembly characteristics and hole transport performance.Using 4-acetamino phenol and haloalkane as starting materials,the target molecules 7-C1,7-C6 and 7-C12 with different alkoxy chains were successfully synthesized through an optimized reaction route.The structures of the target molecules and their important intermediates were identified by ¹H NMR,¹³C NMR and mass spectrometry.The self-assembly properties of compounds 7-C1,7-C6 and 7-C12 were studied by UV-Vis absorption spectroscopy,fluorescence spectroscopy,concentration gradient¹H NMR and polarizing microscope.We found that all of them are self-assembled in the solvent.It was found that the compounds 7-C1,7-C6 and 7-C12 will not compete with the perovskite light-absorbing layer in terms of light absorption by analysing the UV-vis absorption spectroscopy,so they won't affect the utilization of sunlight.The optimized molecular structure,electron cloud distribution and frontier molecular orbitals of compounds 7-C1,7-C6 and 7-C12 were studied by using quantum chemical calculation.The hole transport properties of them were investigated by electrochemical performance test,thermal stability test and film formation performance test,and it was found that the energy levels of the three molecules can match the perovskite layer and their thermal stability is good.However,the compound 7-C1 had poor film formability and was not suitable for use as a HTM;7-C6 and 7-C12 had good film forming properties and could be applied as HTMs to Perovskite solar cells(PSCs).The perovskite layer was passivated using compound 7-C12 and the perovskite solar cell was assembled using Spiro-OMe TAD as the HTM layer,with a perovskite solar cell based on pure Spiro-OMe TAD as a reference.J-V curve showed that after adding 7-C12 as the passivation layer to PSCs,J_sc increased by 1.18 m A cm^-2 and PCE increased by 0.68%,comparing to the Spiro-OMe TAD based PSCs,indicating that the supramolecular polymer 7-C12 can effectively passivate the defects of the perovskite layer.