Investigation On The Crystal Growth Mechanism Of Cobalt Phthalocyanine And Its Fluorinated Derivatives And The Performance Of Field-effect Device

Organic field-effect transistors?OFETs?have attracted considerable attention as their applications in integrated circuit,sensor,electronic paper,flexible display.Phthalocyanine cobalt and its fluorinated derivatives had large?-conjugated structure,which had good chemical and thermal stability,excellent optical and electrical performance.This paper aimed at the study on synthesis,crystal growth and field-effect performance of Co Pc,F₈CoPc and F₁₆Co Pc.The Co Pc?F₈Co Pc and F₁₆Co Pc were synthesized through phthalonitrile and its derivatives with yield of 70.49%,64.44%,and 58.27%respectively.Target products were characterized by MALDI-TOF-MS,IR,and UV-Vis.The nano-and micro-architectures were fabricated by PVD method.Crystal morphologies were controlled via furnace and substrate temperature,system pressure and growth time.For Co Pc,the emergence of hollow and“broom”architectures depends on pressure.At high temperature,cluster for F₈Co Pc and cluster or“flower”for F₁₆Co Pc appeared.Morphologies evolution process of complex architecture crystals had been clearly revealed,and the relationship of morphology and crystal phases was investigated by XRD and UV-vis.The result indicated that crystal phase of Co Pc and F₈CoPc did not change with furnace temperature raised,while crystal phase of F₁₆Co Pc transformed by raising furnace temperature.The SiO₂ insulation layer was modified via OTS,and the effect of volume fraction,soaking time and temperature on surface morphology and wettability were investigated.The best condition of modifying insulation layer is that volume fraction of OTS solution,soaking temperature and time is 1%,5?and 90 min respectively.Optimized the preparation process of the devices.The FET based on Co Pc,F₈CoPc and F₁₆Co Pc were prepared with carrier mobility of 0.56,0.1 and 0.23cm²·V^-1·s^-1 rerspectively.The introduction of fluorine atoms had achieved the transformation of p-type to n-type device performance.Conbined with the theorycalculation,the effect of the fluorine atom on the molecular level,the frontier molecular orbital and reorganization energy were studied.