Co掺杂MAPbI3中FA的应力释放与费米能级调控及其在高效无传输层光电探测器中的应用OA

B-site metal doping has potentials to suppress both the point defects and boundary defects of lead halide perovskites,while the differences in ionic radii of dopants and parent atoms induce remarkable local strains that se-verely limit the sizes of crystalline grains in thin films.Herein,FA has been introduced into Co-doped MAPbI3 to re-lax the local strains to improve the qualities of MAPbI3 thin films.Experimental and theoretical studies suggest that Co doping induced remarkable local tensile strains,which are effectively relaxed by doping FA.Further studies sug-gest that doping of FA decreases the boundary defects and tunes the Fermi energy of Co-doped MAPbI3 thin films si-multaneously,which effectively suppresses non-radiative recombination and improves the carrier transport at MAPbI3/ITO interfaces.On these bases,efficient transport layer-free MAPbI3/ITO photodetectors with the responsivity and external quantum efficiency(EQE)as high as 0.094 A/W and 28％at zero bias have been achieved.These results have provided promising pathways for obtaining efficient transport-layer-free perovskite photodetectors in the future.