Effects Of Surface Polarization And Spinterfaces In Organic-Inorganic Hybrid Perovskites

Organic-inorganic hybrid perovskites(OIHPs)are novel multi-functional materials with simultaneously semiconducting,ferroelectric,and spin-orbit coupling(SOC)properties.These three physical properties make the photovoltaic,light emitting,magneto-optical effects connected together.By overall considering and applying the above three properties,it will promote developments of photovoltaic,light emitting,magneto-optical effects with innovative methods.This project is based on one of the representative OIHPs,CH3NH3PbI3-xClx,related solar cells and spintronic devices.To mainly apply impedance spectroscopy,magneto-resistance(MR),electron paramagnetic resonance(EPR),magneto-photocurrent and some relevant theoretical models for characterizing and studying charge and spin-polarized electronic transport behaviors in those devices.To deeply explore the surface polarization and recombination in the CH3NH3PbI3-xClx based solar cell;and,the formation of spinterface between CH3NH3PbI3-xClx and the ferromagnet Ni.The project aims at elucidating the following key scientific issues based on the two systems:1.In the photovoltaic aspect,under working conditions and steady states,how surface traps and photo-/electrically induced polarizations impact on surface charge accumulation and electron-hole recombination.Meanwhile,the depletion capacitance(Cdl)due to the surface depletion region of CH3NH3PbI3-xClx is suppressed at a weak light intensity(1×10-3 mW/cm2).Its surface capacitance(Cs)exists only at low excitation frequency.2.In the opto-spintronic aspect,with the characterization method of magneto-resistance for Ni/CH3NH3PbI3-xClx/Ni based perovskite spin-valve,to unravel the formation of the spinterface between the ferromagnet Ni and CH3NH3PbI3-xClx due to the spin-dependent orbital hybridization.It thus helps to elucidate impact of the spinterface on the spin-polarized electronic transport in the spin-valves.These two have important contributions to the development of organic-inorganic hybrid opto-spintronics.