2 research outputs found
Dualâlogicâinâmemory implementation with orthogonal polarization of van der Waals ferroelectric heterostructure
Abstract The rapid advancement of AIâenabled applications has resulted in an increasing need for energyâefficient computing hardware. Logicâinâmemory is a promising approach for processing the data stored in memory, wherein fast and efficient computations are possible owing to the parallel execution of reconfigurable logic operations. In this study, a dualâlogicâinâmemory device, which can simultaneously perform two logic operations in four states, is demonstrated using van der Waals ferroelectric fieldâeffect transistors (vdW FeFETs). The proposed dualâlogicâinâmemory device, which also acts as a twoâbit storage device, is a single bidirectional polarizationâintegrated ferroelectric fieldâeffect transistor (BPIâFeFET). It is fabricated by integrating an inâplane vdW ferroelectric semiconductor SnS and an outâofâplane vdW ferroelectric gate dielectric materialâCuInP2S6. Four reliable resistance states with excellent endurance and retention characteristics were achieved. The twoâbit storage mechanism in a BPIâFeFET was analyzed from two perspectives: carrier density and carrier injection controls, which originated from the outâofâplane polarization of the gate dielectric and inâplane polarization of the semiconductor, respectively. Unlike conventional multilevel FeFETs, the proposed BPIâFeFET does not require additional preâexamination or erasing steps to switch from/to an intermediate polarization, enabling direct switching between the four memory states. To utilize the fabricated BPIâFeFET as a dualâlogicâinâmemory device, two logical operations were selected (XOR and AND), and their parallel execution was demonstrated. Different types of logic operations could be implemented by selecting different initial states, demonstrating various types of functions required for numerous neural network operations. The flexibility and efficiency of the proposed dualâlogicâinâmemory device appear promising in the realization of nextâgeneration lowâpower computing systems
Electronic and electrocatalytic applications based on solutionâprocessed twoâdimensional platinum diselenide with thicknessâdependent electronic properties
Abstract Platinum diselenide (PtSe2) has shown great potential as a candidate twoâdimensional (2D) material for broadband photodetectors and electrocatalysts because of its unique properties compared to conventional 2D transition metal dichalcogenides. Synthesis of 2D PtSe2 with controlled layer number is critical for engineering the electronic behavior to be semiconducting or semimetallic for targeted applications. Electrochemical exfoliation has been investigated as a promising approach for massâproducing in a costâeffective manner, but obtaining highâquality films with control over electronic properties remains difficult. Here, we demonstrate waferâscale 2D PtSe2 films with preâdetermined electronic types based on a facile solutionâbased strategy. Semiconducting or semimetallic PtSe2 nanosheets with large lateral sizes are produced via electrochemically driven molecular intercalation, followed by centrifugationâbased thickness sorting. Finally, gateâtunable broadband visible and nearâinfrared photodetector arrays are realized based on semiconducting PtSe2 nanosheet films, while semimetallic films are used to create catalytic electrodes for overall water splitting with longâterm stability