scholarly journals Probing Charge Transport Difference in Parallel and Vertical Layered Electronics with Thin Graphite Source/Drain Contacts

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Jiayi Li ◽  
Ko-Chun Lee ◽  
Meng-Hsun Hsieh ◽  
Shih-Hsien Yang ◽  
Yuan-Ming Chang ◽  
...  

AbstractIn the present study, we aim to help improve the design of van der Waals stacking, i.e., vertical 2D electronics, by probing charge transport differences in both parallel and vertical conducting channels of layered molybdenum disulfide (MoS2), with thin graphite acting as source and drain electrodes. To avoid systematic errors and variable contact contributions to the MoS2 channel, parallel and vertical electronics are all fabricated and measured on the same conducting material. Large differences in the on/off current ratio, mobility, and charge fluctuations, between parallel and vertical electronics are evident in electrical performance as well as in charge transport mechanisms. Further insights are drawn from a well-constrained analysis of both temperature-dependent current-voltage characteristics and low-frequency (LF) current fluctuations. This work offers significant insight into the fundamental understanding of charge transport and the development of future layered-materials-based integration technology.

Author(s):  
В.А. Шутаев ◽  
В.Г. Сидоров ◽  
Е.А. Гребенщикова ◽  
Л.К. Власов ◽  
А.А. Пивоварова ◽  
...  

AbstractThe influence of hydrogen on the electrical properties of Pd /n -InP and Pd/oxide/ n -InP structures is studied. It is found that a variation in the cutoff voltage $$\Delta {{U}_{{{\text{cut-off}}}}}$$ in the current–voltage characteristics of the structures under study upon exposure to hydrogen with concentrations of 0–1 vol % in a nitrogen–hydrogen mixture is described by the exponential dependence: $$\Delta {{U}_{{{\text{cut-off}}}}}$$ = a [1 – exp(– b ⋅ N _H)], where N _H is the hydrogen concentration (vol %), and a and b are constants dependent on the type of structures. It is shown that a decisive influence on how the potential-barrier height changes in the Pd / InP and Pd / oxide / InP structures in the presence of H_2 in a gas medium is exerted by a change in the Pd work function in an atmosphere of hydrogen. It is found that, in the structures under study, tunneling and thermal-tunneling charge-transport mechanisms operate at 90–300 K in the presence of hydrogen and without it. With increasing hydrogen concentration in the gas mixture, the predominance of the tunneling charge-transport mechanism becomes more pronounced.


2001 ◽  
Vol 16 (7) ◽  
pp. 1982-1988 ◽  
Author(s):  
R. C. Patil ◽  
S. Radhakrishnan ◽  
Sushama Pethkar ◽  
K. Vijaymohanan

Conducting polyaniline/barium titanate (PANI/BaTiO3) composites exhibiting piezoresistivity properties have been synthesized by the in situ deposition technique by placing a fine grade powder of BaTiO3 in the polymerization reaction mixture. The polyaniline was formed preferentially on the ceramic particles giving a much higher yield for PANI than in absence of the BaTiO3 These composites exhibited piezoresistivity with the piezosensitivity being maximum at a certain composition. The current–voltage characteristics clearly revealed a nonlinear space charge controlled charge transport process. A large hysteresis in these characteristics was also observed which was dependent on the BaTiO3 content in a composite. The various results have been explained on the basis of the charge transport mechanism in the heterogeneous conducting material having insulating domains dispersed in it.


1999 ◽  
Vol 607 ◽  
Author(s):  
S. Kato ◽  
T. Horikoshi ◽  
T. Ohkubo ◽  
T. Iida ◽  
Y. Takano

AbstractThe bulk crystal of silicon germanium was grown by vertical Bridgman method with germanium composition, x, varying from 0.6 to 1.0. The temperature dependent variation of the mobility is indicative of alloy scattering dominantly for the bulk wafer. Phosphorus was diffused in as-grown p-type bulk wafer at 850 °C to form pn-junction, and the diffusion coefficient of phosphorus was evaluated as a function of x. The diffusion behavior of phosphorus in silicon germanium is closely correlated with the germanium self-diffusion with changing x. For specimens with lower content x, P concentration profiles indicated “kink and tail” shape, while it was not observed for higher x. For current-voltage characteristics measurement, an ideality factor was obtained.


2006 ◽  
Vol 957 ◽  
Author(s):  
Yahya Alivov ◽  
Xiao Bo ◽  
Fan Qian ◽  
Daniel Johnstone ◽  
Cole Litton ◽  
...  

ABSTRACTThe conduction band offset of n-ZnO/n-6H-SiC heterostructures fabricated by rf-sputtered ZnO on commercial n-type 6H-SiC substrates has been measured. Temperature dependent current-voltage characteristics, photocapacitance, and deep level transient spectroscopy measurements showed the conduction band offsets to be 1.25 eV, 1.1 eV, and 1.22 eV, respectively.


1999 ◽  
Vol 571 ◽  
Author(s):  
D.S. Ginger ◽  
N.C. Greenham

ABSTRACTWe study injection and transport in thin disordered films of CdSe nanocrystals between metal electrodes, We investigate the current-voltage characteristics of these devices as a function of electrode material, nanocrystal size, and temperature. We also measure the photocurrent response of these devices, and find that the photocurrent action spectra follow the quantum-confined absorption spectra of the nanocrystals. For dissimilar top and bottom electrodes, we find that the devices are highly rectifying. By studying space charge limited currents in these devices, we are able to place a lower bound on the effective carrier mobility in such films, and we find that the effective mobility is strongly field dependent. We find that the conductivity is strongly temperature dependent, and is qualitatively consistent with an activated hopping process at temperatures above 180 K.


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