@article{he_corley_lu_di spigna_he_nackashi_franzon_tour_2009, title={Controllable Molecular Modulation of Conductivity in Silicon-Based Devices}, volume={131}, ISSN={["0002-7863"]}, DOI={10.1021/ja9002537}, abstractNote={The electronic properties of silicon, such as the conductivity, are largely dependent on the density of the mobile charge carriers, which can be tuned by gating and impurity doping. When the device size scales down to the nanoscale, routine doping becomes problematic due to inhomogeneities. Here we report that a molecular monolayer, covalently grafted atop a silicon channel, can play a role similar to gating and impurity doping. Charge transfer occurs between the silicon and the molecules upon grafting, which can influence the surface band bending, and makes the molecules act as donors or acceptors. The partly charged end-groups of the grafted molecular layer may act as a top gate. The doping- and gating-like effects together lead to the observed controllable modulation of conductivity in pseudometal-oxide-semiconductor field-effect transistors (pseudo-MOSFETs). The molecular effects can even penetrate through a 4.92-mum thick silicon layer. Our results offer a paradigm for controlling electronic characteristics in nanodevices at the future diminutive technology nodes.}, number={29}, journal={JOURNAL OF THE AMERICAN CHEMICAL SOCIETY}, author={He, Tao and Corley, David A. and Lu, Meng and Di Spigna, Neil Halen and He, Jianli and Nackashi, David P. and Franzon, Paul D. and Tour, James M.}, year={2009}, month={Jul}, pages={10023–10030} }
 @article{he_lu_yao_he_chen_di spigna_nackashi_franzon_tour_2008, title={Reversible Modulation of Conductance in Silicon Devices via UV/Visible-Light Irradiation}, volume={20}, ISSN={["1521-4095"]}, DOI={10.1002/adma.200703084}, abstractNote={,}, number={23}, journal={ADVANCED MATERIALS}, author={He, Tao and Lu, Meng and Yao, Jun and He, Jianli and Chen, Bo and Di Spigna, Neil Halen and Nackashi, David P. and Franzon, Paul D. and Tour, James M.}, year={2008}, month={Dec}, pages={4541–4546} }
 @article{he_he_lu_chen_pang_reus_nolte_nackashi_franzon_tour_et al._2006, title={Controlled modulation of conductance in silicon devices by molecular monolayers}, volume={128}, ISSN={["1520-5126"]}, DOI={10.1021/ja063571l}, abstractNote={We have controllably modulated the drain current (I(D)) and threshold voltage (V(T)) in pseudo metal-oxide-semiconductor field-effect transistors (MOSFETs) by grafting a monolayer of molecules atop oxide-free H-passivated silicon surfaces. An electronically controlled series of molecules, from strong pi-electron donors to strong pi-electron acceptors, was covalently attached onto the channel region of the transistors. The device conductance was thus systematically tuned in accordance with the electron-donating ability of the grafted molecules, which is attributed to the charge transfer between the device channel and the molecules. This surface grafting protocol might serve as a useful method for controlling electronic characteristics in small silicon devices at future technology nodes.}, number={45}, journal={JOURNAL OF THE AMERICAN CHEMICAL SOCIETY}, author={He, T. and He, J. L. and Lu, M. and Chen, B. and Pang, H. and Reus, W. F. and Nolte, W. M. and Nackashi, D. P. and Franzon, Paul and Tour, J. M. and et al.}, year={2006}, month={Nov}, pages={14537–14541} }
 @article{di spigna_nackashi_amsinck_sonkusale_franzon_2006, title={Deterministic nanowire fanout and interconnect without any critical translational alignment}, volume={5}, ISSN={["1941-0085"]}, DOI={10.1109/TNANO.2006.876926}, abstractNote={Interfacing the nanoworld with the microworld represents a critical challenge to fully integrated nanosystems. Solutions to this problem have generally required either nanoprecision alignment or stochastic assembly. A design is presented that allows complete and deterministic fanout of regular arrays of wires from the nano- to the microworld without the need for any critical translational alignment steps. For example, deterministically connecting 10-nm wires directly to 3-mum wires would require a translational alignment to within only about 6 mum. The design also allows for nanowire interconnect and is independent of the technology used to fabricate the nanowires, enabling technologies for which alignment remains very challenging. The impact of potential fabrication errors is analyzed and a structure is fabricated that demonstrates the feasibility of such a design}, number={4}, journal={IEEE TRANSACTIONS ON NANOTECHNOLOGY}, author={Di Spigna, Neil H. and Nackashi, David P. and Amsinck, Christian J. and Sonkusale, Sachin R. and Franzon, Paul D.}, year={2006}, month={Jul}, pages={356–361} }
 @article{kriplani_nackashi_amsinck_di spigna_steer_franzon_rick_solomon_reimers_2006, title={Physically based molecular device model in a transient circuit simulator}, volume={326}, ISSN={["1873-4421"]}, DOI={10.1016/j.chemphys.2006.03.003}, abstractNote={Abstract Two efficient, physically based models for the real-time simulation of molecular device characteristics of single molecules are developed. These models assume that through-molecule tunnelling creates a steady-state Lorentzian distribution of excess electron density on the molecule and provides for smooth transitions for the electronic degrees of freedom between the tunnelling, molecular-excitation, and charge-hopping transport regimes. They are implemented in the f REEDA™ transient circuit simulator to allow for the full integration of nanoscopic molecular devices in standard packages that simulate entire devices including CMOS circuitry. Methods are presented to estimate the parameters used in the models via either direct experimental measurement or density-functional calculations. The models require 6–8 orders of magnitude less computer time than do full a priori simulations of the properties of molecular components. Consequently, molecular components can be efficiently implemented in circuit simulators. The molecular-component models are tested by comparison with experimental results reported for 1,4-benzenedithiol.}, number={1}, journal={CHEMICAL PHYSICS}, author={Kriplani, Nikhil M. and Nackashi, David P. and Amsinck, Christian J. and Di Spigna, Neil H. and Steer, Michael B. and Franzon, Paul D. and Rick, Ramon L. and Solomon, Gemma C. and Reimers, Jeffrey R.}, year={2006}, month={Jul}, pages={188–196} }
 @article{sonkusale_amsinck_nackashi_di spigna_barlage_johnson_franzon_2005, title={Fabrication of wafer scale, aligned sub-25 nm nanowire and nanowire templates using planar edge defined alternate layer process}, volume={28}, ISSN={["1873-1759"]}, DOI={10.1016/j.physe.2005.01.010}, abstractNote={We have demonstrated a new planar edge defined alternate layer (PEDAL) process to make sub-25 nm nanowires across the whole wafer. The PEDAL process is useful in the fabrication of metal nanowires directly onto the wafer by shadow metallization and has the ability to fabricate sub-10 nm nanowires with 20 nm pitch. The process can also be used to make templates for the nano-imprinting with which the crossbar structures can be fabricated. The process involves defining the edge by etching a trench patterned by conventional i-line lithography, followed by deposition of alternating layers of silicon nitride and crystallized a-Si. The thickness of these layers determines the width and spacing of the nanowires. Later the stack is planarized to the edge of the trench by spinning polymer Shipley 1813 and then dry etching the polymer, nitride and polysilicon stack with non-selective RIE etch recipe. Selective wet etch of either nitride or polysilicon gives us the array of an aligned nanowires template. After shadow metallization of the required metal, we get metal nanowires on the wafer. The process has the flexibility of routing the nanowires around the logic and memory modules all across the wafer. The fabrication facilities required for the process are readily available and this process provides the great alternative to existing slow and/or costly nanowire patterning techniques.}, number={2}, journal={PHYSICA E-LOW-DIMENSIONAL SYSTEMS & NANOSTRUCTURES}, author={Sonkusale, SR and Amsinck, CJ and Nackashi, DP and Di Spigna, NH and Barlage, D and Johnson, M and Franzon, PD}, year={2005}, month={Jul}, pages={107–114} }
 @article{amsinck_di spigna_nackashi_franzon_2005, title={Scaling constraints in nanoelectronic random-access memories}, volume={16}, ISSN={["1361-6528"]}, DOI={10.1088/0957-4484/16/10/047}, abstractNote={Nanoelectronic molecular and magnetic tunnel junction (MTJ) MRAM crossbar memory systems have the potential to present significant area advantages (4 to 6F2) compared to CMOS-based systems. The scalability of these conductivity-switched RAM arrays is examined by establishing criteria for correct functionality based on the readout margin. Using a combined circuit theoretical modelling and simulation approach, the impact of both the device and interconnect architecture on the scalability of a conductivity-state memory system is quantified. This establishes criteria showing the conditions and on/off ratios for the large-scale integration of molecular devices, guiding molecular device design. With 10% readout margin on the resistive load, a memory device needs to have an on/off ratio of at least 7 to be integrated into a 64 × 64 array, while an on/off ratio of 43 is necessary to scale the memory to 512 × 512.}, number={10}, journal={NANOTECHNOLOGY}, author={Amsinck, CJ and Di Spigna, NH and Nackashi, DP and Franzon, PD}, year={2005}, month={Oct}, pages={2251–2260} }
 @article{seminario_ma_agapito_yan_araujo_bingi_vadlamani_chagarlamudi_sudarshan_myrick_et al._2004, title={Clustering effects on discontinuous gold film NanoCells}, volume={4}, ISSN={["1533-4899"]}, DOI={10.1166/jnn.2004.104}, abstractNote={Reproducible negative differential resistance (NDR)-like switching behavior is observed in NanoCells. This behavior is attributed to the formation of filaments and clusters between the discontinuous gold films. Control experiments are performed by self-assembly of insulating molecules between the gold islands and conducting molecules on these islands. Additional control experiments are performed by removing the filaments and clusters between islands using a piranha bath. The results are consistent with theoretical predictions and extend the domain of molecular electronics based in organic molecules to include nanosized clusters as active units. This facilitates a scenario where synthetically accessible organic molecules, with defined characteristics, can be adjusted by metallic nanoclusters as an in situ fine-tuning element, able to compensate for the lack of addressing in the nanosize regime.}, number={7}, journal={JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY}, author={Seminario, JM and Ma, YF and Agapito, LA and Yan, LM and Araujo, RA and Bingi, S and Vadlamani, NS and Chagarlamudi, K and Sudarshan, TS and Myrick, ML and et al.}, year={2004}, month={Sep}, pages={907–917} }
 @article{tour_cheng_nackashi_yao_flatt_st angelo_mallouk_franzon_2003, title={NanoCell electronic memories}, volume={125}, ISSN={["1520-5126"]}, DOI={10.1021/ja036369g}, abstractNote={NanoCells are disordered arrays of metallic islands that are interlinked with molecules between micrometer-sized metallic input/output leads. In the past, simulations had been conducted showing that the NanoCells may function as both memory and logic devices that are programmable postfabrication. Reported here is the first assembly of a NanoCell with disordered arrays of molecules and Au islands. The assembled NanoCells exhibit reproducible switching behavior and two types of memory effects at room temperature. The switch-type memory is characteristic of a destructive read, while the conductivity-type memory features a nondestructive read. Both types of memory effects are stable for more than a week at room temperature, and bit level ratios (0:1) of the conductivity-type memory have been observed to be as high as 10(4):1 and reaching 10(6):1 upon ozone treatment, which likely destroys extraneous leakage pathways. Both molecular electronic and nanofilamentary metal switching mechanisms have been considered, though the evidence points more strongly toward the latter. The approach here demonstrates the efficacy of a disordered nanoscale array for high-yielding switching and memory while mitigating the arduous task of nanoscale patterning.}, number={43}, journal={JOURNAL OF THE AMERICAN CHEMICAL SOCIETY}, author={Tour, JM and Cheng, L and Nackashi, DP and Yao, YX and Flatt, AK and St Angelo, SK and Mallouk, TE and Franzon, PD}, year={2003}, month={Oct}, pages={13279–13283} }