International Journal of Nanoelectronics and Materials Volume 11, No. 3, July 2018 [333-346] Contemplating Nanometer Scale Transport Characteristics through Aromatic Molecules Based Molecular Devices Rajan Vohra 1* and Ravinder Singh Sawhney 2 1,2 Department of Electronic Technology, Guru Nanak Dev University, Amritsar (Punjab). Received 26 October 2017; Revised 4 January 2018; Accepted 23 April 2018 ABSTRACT In this research article, we contemplate the quantum transport properties through a single molecular junction comprising of Azulene (C10H8) sandwiched between two semi-infinite gold (Au) electrodes and compare the transport properties with its higher derivative Anthracene (C14H10) based device having similar geometrically optimized data. By modeling this device, we evaluate vital transport parameters like current, conductance, transmission spectra, HOMO-LUMO gap and rectification ratio using a combination of non-equilibrium green’s function and extended Huckle formalism. We observe that Au-C10H8-Au device exhibit higher current in spite of having lower conductance as compared to Au-C14H10-Au device within a variegated bias range. However, Azulene based device has the advantage of getting fabricated as a molecular wire because the charge transfer through this molecule is comparatively stabilized. This property can allow us to produce a molecular diode, which in turn can give us further insight to design molecular devices which can replicate the conventional semi-conductor devices. On the other hand, Anthracene based molecular devices can be utilized in electronic applications such as organic solar cells, OLEDS (Organic Light Emitting Diodes) etc. Keyword: Azulene, Anthracene, HOMO-LUMO Gap, Non-Equlibrium Green’s Function, Extended Huckle Theory. 1. INTRODUCTION In 1974, Aviram and Ratner [1] suggested an organic molecular system in which they observed the current rectification by composing a donor and an acceptor group joined by a carbon bridge having single bonds. Ratner later revealed [2] that the realization of such a proposal was “somewhere between science fiction and state-of-the-art”. It was in mid-1990s that the first noteworthy attempt of charge transport through single molecules were reported [3,4]. At that time formation of electrode–molecule–electrode junction was not optimally feasible. Moreover, managing the unavoidable variability was also not easy to predict the properties of single molecules. In 2003, Nongjian Tao and Bingqian Xu developed a method to address these concerns. They made use of STM as an electrically active ‘fishing rod’ that selects up molecules from the surface of electrode [5]. The tip of STM interacts with the molecules on the surface and then slowly moves away. The molecules having end-group anchors to form the covalent bonds to both the electrode and the STM tip bridge the two. In this way, an electrode–molecule–electrode junction is formed. Molecular electronics is being anticipated as an alternative to silicon based conventional electronics in post-CMOS era. Molecules encompass distinctive functions with many applications that complement the silicon based microelectronics. *Corresponding Author: rajanvohraece.rsh@gndu.ac.in