bio-molecular nano scale devices using first principle paradigm: a comprehensive survey

Computational study plays an important role to discover the potential of the bio-inspired nano scale molecular devices.  density functional theory (dft) is one of the popular methods to calculate the properties of the molecules which can not be possible with ab initio process, preferably for transition metals. this method is important for electronic structure calculation along with structure of molecules, atoms and solids can also be calculated using this dft method. it is the quantitative method to understand the material properties using the laws of fundamental quantum mechanics. the key benefit of non equilibrium greens’ function (negf) is that it preserves the wave character of the electrons, which leads to a extremely precise description of nanoscale. combining theses dft and negf calculation first principle approach reveal the quantum-ballistic properties of atomic scale electronic structures which is therefore attracts the researchers for their innovative calculations for nano scale device modelling. in this paper, we briefly discuss the review on various bio-molecular devices and their significances. now-a-days bio inspired devices show more attractions due to their versatility compared to the conventional electronic devices. these nano scale devices are popular due to their performance, speed and high charge transmission properties compared to other conventional semi-conductor devices.  this review work presents some experimental works at the molecular level along with a variety of research works that are performed based on first principle approach. several case studies prevails the importance of dft and negf based first principle approach for nano scale device modelling.