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terms of switching performance when its thickness approaches atomic thickness. [3] Besides of its atomic thickness, TMDCs have no dangling or broken bonds on their surfaces, which gives another advantage over silicon by suppressing scattering of the charge carriers from the surfaces.However, TMDCs have major issues hindering its adoption in microelectronics to replace the silicon; one is the reduction of the contact resistance, and the other one is the modulation of doping. Formation of Schottky barrier between a contacting metal and a TMDC is known from the early stage of the TMDC research. [4] Ohmic contacts have been demonstrated by several methods, such as insertion of graphene between the metal and TMDC, [5] or use of a specific metal, like Bi. [6] Thus there has been progress toward realizing the ohmic contact on the TMDC. The most intensively researched TMDC materials, such as MoS 2 , WS 2 , HfS 2 , HfSe 2 are electron-doped (n-doped or n-type) materials due to the sulfur vacancies, [7] and MoSe 2 , MoTe 2 , WSe 2 are ambivalent. [4] There are lots of on-going efforts to find a stable and reliable hole-doping (p-doped or p-type) method for the above materials, [8] albeit the number of reports on the p-doping is still relatively smaller than that of the n-doping. Representatively, there are three groups of method, charge Development of a reliable doping method for 2D materials is a key issue to adopt the materials in the future microelectronic circuits and to replace the silicon, keeping the Moore's law toward the sub-10 nm channel length. Especially hole doping is highly required, because most of the transition metal dichalcogenides (TMDC) among the 2D materials are electron-doped by sulfur vacancies in their atomic structures. Here, hole doping of a TMDC, tungsten disulfide (WS 2 ) using the silicon substrate as the dopant medium is demonstrated. An ultralow-power current sourcing transistor or a gated WS 2 pn diode is fabricated based on a charge plasma pn heterojunction formed between the WS 2 thin-film and heavily doped bulk silicon. An ultralow switchable output current down to 0.01 nA µm −1 , an off-state current of ≈1 × 10 −14 A µm −1 , a static power consumption range of 1 fW µm −1 -1 pW µm −1 , and an output current ratio of 10 3 at 0.1 V supply voltage are achieved. The charge plasma heterojunction allows a stable (less than 3% variation) output current regardless of the gate voltage once it is turned on.

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We investigated the performance improvement of tin disulfide channel transistors by graphene contact configurations. From its two-dimensional nature, graphene can make electric contacts only at the outermost layers of the channel. For intralayer current flow, two graphene flakes are contacted at the channel's top or bottom layer. For interlayer current flow, one flake is contacted at the top and bottom of each layer. We compared the transistor performance in terms of current magnitude, mobility, and subthreshold swing between the configurations. From such observations, we deduced that device characteristics depend on resistivity or doping level of individual graphene flakes. We also found that interlayer flow excels in the on-current magnitude and the mobility, and that top-contact configuration excels in the subthreshold swing.

To assess the influence of bridge structure manipulation on the electrochemical performance of π-conjugated molecule-bridged silicon quantum dot (Si QD) nanocomposite (SQNC) anode materials, we prepared two types of SQNCs...