# Nanofabrication Techniques in Large-Area Molecular Electronic Devices
## 1 Introduction
A potential successor of our current technology, must not only fulfill the same expectations as cmos but also outperform prevalent technology in at least a number of several clue aspects, including power consumption, mass production, fabrication costs, and performance, and overcome current functionalities, i.e., fully enter in the \"More than Moore\" path [8]. These efforts are being made from a multidisciplinary point of view, for which the contribution of physicists, chemists, and engineers is essential for overcoming the enormous challenges ahead. In the above-described scenario, molecular electronics emerges as a great promise. Molecular electronics is based on the idea of using molecules as functional units in circuitry to permit, control, and manipulate the movement of electrical charges between two electrodes [9]. The fundamental tool for understanding electrical transport through these two electrodes is the creation of electrode \(|\) molecule \(|\) electrode molecular junctions [10; 11; 12; 13; 14]. The official birth of molecular electronics is widely recognized as 1974, with the publication of the seminal paper from [PERSON] and [PERSON] that proposed (theoretically) that a single-molecule could act as a rectifier [15]. Intense work in the field for more than four decades has included the development of methodologies based on scanning tunneling microscopy (STM) or conducting atomic force microscopy (c-afm) for measuring the electrical properties of single-molecules and molecular assemblies [16; 17; 18; 19; 20; 21; 22]. These studies have resulted in a growing understanding of the key parameters that determine the electrical properties of molecular junctions (molecular backbone [12; 23], chemical anchoring groups [24; 25; 26], conformation [27], metal complexation [28], redox state [18; 29; 30; 31], electrode material [32; 33; 34; 35], and if applicable, the characteristics of the medium: Solvent [36], pH [37], etc. ), as well as the mechanisms behind electronic transport in molecular junctions [38; 39; 40]. In particular, molecular wires [41], switches [42], diodes [43], rectifiers [44], transistors [45], and single-molecule light-emitting diodes [46] have already been demonstrated in the laboratory and make feasible the idea of integrating molecules into electrical circuits. The expectations in molecular electronics lie on its several advantages as compared to the above-described Si-based technology with relevant contributions in the field [47; 48; 49; 50], making emphasis on applications of molecular electronics in solar-energy harvesting, thermoelectricity, catalysis, or molecular sensing. Another field of remarkable importance today is the study of single-molecule chemical reactions within the molecular junction [51; 52; 53]. The use of molecules has several advantages--both from a fundamental and an applied point of view. The most remarkable phenomena observed in molecular junctions and their promising perspectives in a short-term future technology result from:  
* The size of the molecules--in the order of a few nanometers--that may enable heightened capacities, faster performance, and high integration density, with millions of identical electric machines each of them as small as one molecule [50]. * Molecular junctions exhibit a plethora of rich and tunable physicochemical properties--different from those exhibited by molecular materials in bulk--since charge transport is governed by quantum mechanics at the molecular scale. These phenomena at the nanoscale include quantum mechanical interference, the Coulomb blockade, and the Kondo effect [12; 54].