Numerical Simulation Design Of Molecular Transistor

The miniaturization of the subunit of computer,transistor,will undergo inevitable difficulties due to physical principles.When the size of the transistors shrink to smaller than 100 nm,quantum mechanics dominates,and the transistors no longer function usefully.To continue the miniaturization of the device down to molecular scale,present-day microelectronic device designs must be replaced with new designs that take advantage of the quantum mechanical efiects.In this thesis,the influence of bias is included into the effective potential in Schrodinger equation from first principles method.To test the reliability of the algorithm,we calculate current-voltage characteristics for the well studied alkanethiol junction.The results are consistent with the previous theoretical and experimental studies.In order to demonstrate the validity of the program for designing the molecule transistor,we design an amino-substitued butnanethiol junction by substituting H with -NH₂ in the butanethiol junction.The size is only around lnm.The new design keeps both the good match between the alkanethiol juncion and the electrode and the characteristic of self-assembly,which make it possible to integrate a large amount of single molecule transistors in a small region at low cost.Calculations using our algorithm show that the designed amino-substitued butnanethiol junction can be used as transistors.This result shows the algorithm proposed in this thesis can be used to design the molecular transistors.