Multi‐State Heterojunction Transistors Based on Field‐Effect Tunneling–Transport Transitions

Abstract

A monolithic ternary logic transistor based on a vertically stacked double n‐type semiconductor heterostructure is presented. Incorporation of the organic heterostructure into the conventional metal‐oxide‐semiconductor field‐effect transistor (MOSFET) architecture induces the generation of stable multiple logic states in the device; these states can be further optimized to be equiprobable and distinctive, which are the most desirable and requisite properties for multivalued logic devices. A systematic investigation reveals that the electrical properties of the device are governed by not only the conventional field‐effect charge transport but also the field‐effect charge tunneling at the heterointerfaces, and thus, an intermediate state can be finely tuned by independently controlling the transition between the onsets of these two mechanisms. The achieved device performance agrees with the results of a numerical simulation based on a pseudo‐metal–insulator–metal model; the obtained findings therefore provide rational criteria for material selection in a simple energetic perspective. The operation of various ternary logic circuits based on the optimized multistate heterojunction transistors, including the NMIN and NMAX gates, is also demonstrated.

Optimizing the photoresponse enhancement in a hybrid inorganic–organic phototransistor with an amorphous indium gallium zinc oxide channel layer and PTCDI-C13 photoactive layer

“…A simple perylene derivative with no additional functional groups besides a carbon chain, PTCDI-C 5 , was used in a color sensing circuit without an external color filter, demonstrating potential applications for narrowband organic semiconductors. 38 While perylene derivatives were not applied as photoresponsive layers with a-IGZO, PTCDI-C 8 was reportedly utilized as a charge injection layer inserted between the oxide film and Al electrode, 39 demonstrating good charge transport between the organic and oxide films, which is expected to be an advantage for the fabrication of a bilayer phototransistor. This paper reports the fabrication of a hybrid inorganicorganic phototransistor with an a-IGZO channel layer and an N,N 0 -ditridecyl-3,4,9,10-perylenetetracarboxylic diimide (PTCDI-C 13 ) photoactive layer.…”

Multivalued Logic for Optical Computing with Photonically Enabled Chiral Bio-organic Structures

“…Increasing demands for massive data processing at human–machine interfaces require low power consumption and the energy-restricted issues of end nodes. , As one of the promising technologies to surpass current computing performances and substantially increase information density per given unit device, quantum computation has been developed to explore ternary, quaternary, or even higher multivalued logic systems (MVLS) with possible integration. − It promises to be superior in processing large amounts of data information at the same time, such as real-time image visualization and analysis. − A typical example is a ternary logic with three threshold voltages ( V th ): GND (ground), intermediate voltage, and V DD (supply voltage), , which have been realized by tunneling diodes , and anti-ambipolar transistors (AAT). − They showed a negative differential resistance with the folded current–voltage characteristics (N-shaped I – V curve), based on two-dimensional transition metal dichalcogenides (TMDCs), including MoS 2 and WSe 2 . ,, However, it is not possible to systematically control the electrical response due to a dominant Fermi-level pinning effect. , Compared to the 2D materials, bio-organic materials, such as proteins, nucleic acids, enzymes, and supramolecular hydrogels, exhibit potential for designing multivalued logic systems due to their well-ordered structure, highly specific recognition, and stimuli-responsive behavior. , Also, the bio-organic materials could convert different inputs, including chirality of light and chemical species to optoelectrical output signals. − …”

Area-Selective Chemical Doping on Solution-Processed MoS2 Thin-Film for Multi-Valued Logic Gates

“…For example, a quaternary logic system requires only half the number of devices and interconnection lines to achieve device performance similar to that of a binary logic system . These potential advantages have motivated the exploration of various material platforms based on heterostructures such as core/shell nanowires, van der Waals (vdW) p–n heterojunctions, − nanoparticle-embedded dielectric layers, ,, and organic–inorganic heterojunctions . Consequently, multi-valued devices have been successfully demonstrated through tunneling-based sequential activation ,, and quantum-dot-assisted charge confinement. ,, …”

“…In particular, from a broad range of material selection in two-dimensional (2D) semiconductors, various combinations of p–n heterojunctions have been utilized to demonstrate prototype multivalued logic gates based on antiambipolar or negative differential resistance (NDR) behaviors. − ,, Although the vdW p–n heterojunctions can provide high/precise tunability in multistate electrical transport behavior, the lack of scale-up approaches for individual junction-based demonstrations limits their practical applications. To overcome the scalability limitation, organic–inorganic double n-type semiconductor-based heterojunctions possessing different threshold voltages have been introduced as other types of tunneling-based sequential activation device for ternary logic gate applications . For example, a vertically stacked inorganic indium–gallium–zinc oxide (IGZO) and an organic PTCDI-C8 were sequentially turned on due to their distinctive work functions under a gate voltage sweep, which resulted in ternary electrical behaviors in transfer characteristics.…”

“…For example, a vertically stacked inorganic indium–gallium–zinc oxide (IGZO) and an organic PTCDI-C8 were sequentially turned on due to their distinctive work functions under a gate voltage sweep, which resulted in ternary electrical behaviors in transfer characteristics. Although this approach can demonstrate a stable intermediate state in a wafer-scale device array, additional efforts are required to optimize the band-gap misalignment by modulating a series of elemental compositions of IGZO …”