The Study Of Charge Trapping Properties And Mechanism For The Small Organic Molecules By The Electrostatic And Kelvin Probe Force Microscopy

Small organic molecules materials are widely applied in organic electrical devices because of their flexibility,aptness for trimming,environmental friendliness and low cost.One of the applications is charge-trapping layer in organic memory devices.As a candidate for next generation high-density memory devices,charge-trapping memory device has been a focus for fundamental research as well as industrial development.The location and space distribution of charges in the trapping layer directly affect the devices' ability of writing,erasing and storing,making them important contributors to the quality of devices.To further understand the material's electrical quality,ulteriorly investigate its optical-electrical character and ameliorate its performance,we extend our research of the material's electrical character on a micro-nano basis.In recent years,EFM and KPFM stand out in electricity research with their high resolution rate and wide application on various materials.Using EFM and KPFM,we researched small organic molecules materials and obtained electrical characters of relative material,including:?1?In our quality and quantity analysis on the injecting and storing ability of charges trapped by sterically hindered organic semiconductor DSFXPY films,we compared the storage ability of DSFXPY films with different thickness,discovering that there is no obvious horizontal distribution for DSFXPY films,and that the storage ability of holes is better than charges in the film.?2?In our quality and quantity analysis on the injecting and storing ability of charges trapped by sterically hindered organic semiconductor PS/SFDBAO mixed films,we compared the storage ability of PS/SFDBAO mixed films with different impurity densities,discovering that the mix of SFDBAO and PS can enormously improve the density and ability of storage.PS/SFDBAO mixed film has no obvious horizontal distribution,with PS/SFDBAO-10% featuring best hole storage ability.?3?In our quality and quantity analysis on the injecting and storing ability of n-type organic micromolecule PS/C₆₀ mixed films,we compared the storage ability of n-type organic micromolecule PS/C₆₀ mixed films with different impurity densities,finding that PS/C₆₀-15% possesses best storage ability.Besides,we focused on the distribution and erasing mechanism of trapped charges in the film,finding that electrons are more apt to erasing in PS/C₆₀ mixed film;although horizontal and vertical distribution co-exist in PS/C₆₀ mixed film,vertical distribution is the leading mechanism.Our research proved that both DSFXPY and PS/SFDBAO possess great charge rounding ability and storage ability,making them ideal materials for high density organic storage devices.the longitudinal loss is the main mechanism for the decay of the trapped charges in PS/C₆₀ mixed film.With deeper research on the micro-nano electrical characters of organic materials,we believe that organic micromolecule film will keep showing its unique physical characters and be fully applied in organic electricity.