Research On Fabrication And Performance Of Thin Film Transistors Based On Titanium Phthalocyanine Dichloride

This article focuses on an axially substituted phthalocyanine material: titanium phthalocyanine(Ti Cl2Pc),which has not been found in TFT devices in the reported literature.Therefore,this article applies Ti Cl2 Pc as an active layer material to organic thin film transistors.The device is produced.At the same time,in order to solve the problem that the active layer and the insulating layer have a lot of interface defects during the preparation of Ti Cl2 Pc OTFT,which reduces the transistor mobility,the interface between the active layer and the insulating layer is modified by organosilane reagents and weak epitaxial growth.The growth behavior of organic thin films further improves the quality of organic thin films and the electrical performance of OTFT devices.The effect of organosilane reagent modification on the properties and morphology of Ti Cl2 Pc OTFT devices was first studied.The surface of the Si O2 insulating layer was modified with octadecyltrichlorosilane(OTS)reagent.Ti Cl2 Pc OTFT was tested for I-V characteristics and atomic force morphology.The experimental results show that the performance of Ti Cl2 Pc OTFT devices modified by OTS is significantly improved.In addition,compared with the unmodified Ti Cl2 Pc thin film,the Ti Cl2 Pc thin film modified by OTS has a more smooth and continuous film surface,fewer surface defects,and larger grain size,which is more conducive to the generation and transport of carriers.Secondly,the effect of weak epitaxial growth on the performance and film morphology of Ti Cl2 Pc OTFT devices was studied: BP2 T,an organic small molecule material,was used as the induction layer,and BP2 T thin films of 4nm,6nm,and 8nm were deposited on the surface of the Si O2 insulating layer using vacuum deposition technology.Ti Cl2 Pc OTFT was tested for I-V characteristics and atomic force morphology.The experimental results show that the three groups of devices modified by BP2 T have improved performance compared with unmodified devices,and the carrier mobility of the device is highest when the thickness of BP2 T is 8nm.Compared with the single-layer Ti Cl2 Pc thin film,the Ti Cl2 Pc thin film grown on three groups of BP2 T has a smoother surface,larger grain size and fewer surface defects.Among them,the Ti Cl2 Pc film grown on the 8nm BP2 T induction layer is the most flat and continuous,with the largest grain size and the least surface defects,which is most conducive to the generation and transport of carriers.Finally,the cause of the p-type transmission characteristics of titanium phthalocyanine dichloride was studied in detail.Based on the analysis of molecular energy levels and the distribution of atomic charge and charge in the molecule,the effects of substituents(axial ligands,central metals)on the carrier transport characteristics of Ti Cl2 Pc were studied.The lowest unoccupied molecular orbital energy level(LUMO)of the phthalocyanine compound was determined using a CHI660 D electrochemical workstation.X-rayphotoelectron spectroscopy(XPS)was performed on the atomic charge and electric energy distribution of a series of phthalocyanine compounds using a Thermo ESCALAB 250X-ray photoelectron spectrometer.The results show that the electronegativity of the axial ligand and the central metal affect the LUMO energy level of the molecule and the distribution of the atomic charge and charge in the molecule,so that Ti Cl2 Pc exhibits p-type transmission characteristics.