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This paper reports the fabrication of silicon PN diode by using DNA nanostructure as the etching template for SiO₂and also as then-dopant of Si. DNA nanotubes were deposited ontop-type silicon wafer that has a thermal SiO₂layer. The DNA nanotubes catalyze the etching of SiO₂by HF vapor to expose the underlying Si. The phosphate groups in the DNA nanotube were used as the doping source to locallyn-dope the Si wafer to form vertical P-N junctions. Prototype PN diodes were fabricated and exhibited expected blockage behavior with a knee voltage ofca.0.7 V. Our work highlights the potential of DNA nanotechnology in future fabrication of nanoelectronics.

 

The Diels–Alder (DA) reaction, a classic cycloaddition reaction involving a diene and a dienophile to form a cyclohexene, is among the most versatile organic reactions. Theories have predicted thermodynamically unfavorable DA reactions on pristine graphene owing to its low chemical reactivity. We hypothesized that metals like Ni could enhance the reactivity of graphene towards DA reactions through charge transfer. The results indeed showed that metal substrates enhanced the reactivity of graphene in the DA reactions with a diene, 2,3-dimethoxy butadiene (DMBD), and a dienophile, maleic anhydride (MAH), with the activity enhancement in the order of Ni > Cu, and both are more reactive than graphene supported on silicon wafer. The rate constants were estimated to be two times higher for graphene supported on Ni than on silicon wafer. The computational results support the experimentally obtained rate trend of Ni > Cu, both predicted to be greater than unsupported graphene, which is explained by the enhanced graphene–substrate interaction reflected in charge transfer effects with the strongly interacting Ni. This study opens up a new avenue for enhancing the chemical reactivity of pristine graphene through substrate selection. 

This paper reports the fabrication and mechanical properties of macroscale graphene fibers (diameters of 10 to 100 μm with lengths upwards of 2 cm) prepared from a single sheet of single-layer graphene grown via chemical vapor deposition (CVD). The breaking strength of these graphene fibers increased with consecutive tensile test measurements on a single fiber, where fiber fragments produced from a prior test exhibited larger breaking strengths. Additionally, we observed an overall reduction of surface folds and wrinkles, and an increase in their alignment parallel to the tensile direction. We propose that a foundation of this property is the plastic deformations within the fiber that accumulate through sequential tensile testing. Through this cyclic method, our best fiber produced a strength of 2.67 GPa with a 1 mm gauge length. 

This review surveys recent developments of DNA nanotechnology related to its applications in nanoelectronics industry. The authors start with a brief introduction of DNA nanostructures, followed by a focused discussion of various DNA‐based fabrication approaches that are relevant to the semiconductor industry, including DNA‐based doping of semiconductor materials, DNA‐based fabrication of nanostructures of metallic, dielectric, and semiconductor materials, and DNA‐based lithographic patterning of Si, SiO₂, metal, graphene, and polymer substrates. Examples of DNA‐templated fabrication of prototype nanoscale transistors and sensors are highlighted. Finally, major technical challenges facing the future applications of DNA nanotechnology in nanoelectronics and beyond are discussed.