Effect Of Length On The Position Of Negative Differential Resistance And Design Towards Multifunction In Fused Oligothiophenes Based Molecular Device

In recent years, molecular devices have raised significant interdisciplinary interest. Thedevelopment of nanometer-scale electronic devices provides great potential to the nowadaysapplied sciences. Analysis of many attractive properties offered by nano-devices, such asnegative differential resistance (NDR), and rectifying performance shows potentialadvantages of nano-scale structures. The presence of NDR is a useful feature that has a widevariety of circuit applications, such as high-speed switches, high-frequency oscillators,amplifiers, and logic. This behavior has been reported in nanowires, graphene, and nanotubes.In1974, a classic prototype in molecular electronics, a single molecule attached to donor andacceptor groups could function as a diode, was proposed by Aviram and Ratner.Multifunctional molecular devices are important because they can further improve the level ofintegration of molecular circuits in the future.Oligothiophenes (multiple thiophene rings joined by single bonds) are a leading class oforganic semiconductors materials for new technologies. Sabyasachi Sen reported thatNegative differential resistance in fused thiophene trimer. Here, we suggest thatmultifunctional molecular devices can also be realized if different substituents are introducedto oligothiophenes, and the peak positions of NDR can be controlled by changing of thelength of the oligothiophenes. However, for all we have known, this multifunctionalmolecular devices has been few investigated and reported yet, up until now.