Large‐area high quality PtSe₂ thin film with versatile polarity

Abstract

Two‐dimensional (2D) materials have attracted increasing attention for their outstanding structural and electrical properties. However, for mass‐production of field effect transistors (FETs) and potential applications in integrated circuits, large‐area and uniform 2D thin films with high mobility, large on‐off ratio, and desired polarity are needed to synthesize firstly. Here, a transfer‐free growth method for platinum diselenide (PtSe2) films has been developed. The PtSe2 films have been synthesized with various thicknesses in centimeter‐sized scale. Typical FET made from a few layer PtSe2 show p‐type unipolar, with a high field‐effect hole mobility of 6.2 cm2 V−1 s−1 and an on‐off ratio of 5 × 103. The versatile semimetal‐unipolar‐ambipolar transition in synthesized PtSe2 films is also firstly observed as the thickness thinning. This work realizes the large‐scale preparation of PtSe2 with prominent electrical properties and provides a new strategy for polarity's modulation.

Unveiling active sites by structural tailoring of two‐dimensional niobium disulfide for improved electrocatalytic hydrogen evolution reaction

“…Post‐annealing treatment: annealing temperature provides energy to the NbS 2 atoms which facilitate the coalescence, resulting in the larger size of NbS 2 particles starts forming. As the temperature going to increase, new Nb‐S bonds have been created between adjacent particles and different recrystallized obtained, such effects were already reported in others TMDs 46,47 . After that evaporation was started from the top layers of NbS 2 flakes, Nb and S atoms are going to start and thinning of the individual particle leads.…”

“…As the temperature going to increase, new Nb-S bonds have been created between adjacent particles and different recrystallized obtained, such effects were already reported in others TMDs. 46,47 After that evaporation was started from the top layers of NbS 2 flakes, Nb and S atoms are going to start and thinning of the individual particle leads. This thermal thinning of NbS 2 flakes can be understood by the layer-by-layer evaporation model, which assumes that the atoms were evaporated from the top surface at high temperatures.…”

Bio-Separated and Gate-Free 2D MoS2 Biosensor Array for Ultrasensitive Detection of BRCA1

“…However, a good discrimination in a narrow range is difficult to achieve, since the current response caused by the lower concentration change of the target (from 1 fM to 10 fM) is too tiny to distinguish. The shortcoming of the proposed sensor may be solved by replacing MoS 2 with high-mobility or semi-metallic materials (e.g., multilayer PtSe 2 ) [ 44 ]. Nevertheless, the bio-separated and gate-free structure sensor arrays with simple fabrication and biomodification manifest a practicable development of high-performance, low-cost, biocompatible, and reusable biosensor systems.…”

Layered PtSe2 for Sensing, Photonic, and (Opto‐)Electronic Applications

“…i) Summary of the On/Off ratio of a range of FETs based on different PtSe 2 thicknesses. [5,8,21,[26][27][28][29][30][31][32][33] c,d) Reproduced with permission. [5] Copyright 2016, Wiley-VCH.…”

“…In addition, layered PtSe 2 holds great promise for applications in sensors and (opto‐)electronic devices like field‐effect transistors (FETs) and photodetectors (PDs). [ 5,8,21,26–33 ] A thickness‐tunable evolution of the bandgap has been theoretically and experimentally observed in layered PtSe 2 . A direct bandgap of 1.2 eV has been observed in the monolayer limit, this dramatically decreases in few‐layer PtSe 2 and the bulk form is semimetallic.…”