A single-crystalline native dielectric for two-dimensional semiconductors with an equivalent oxide thickness below 0.5 nm

Towards high-performance p-type two-dimensional field effect transistors: contact engineering, scaling, and doping

“…While the Si technology is here to stay [3][4][5], at extremely scaled transistor dimensions, atomically thin channel materials such as mono-and few-layers of transition metal dichalcogenides (TMDs) are being considered as replacement and augmentation for Si to usher a new era for "More (than) Moore" and "Beyond Moore" technologies [6,7]. The recent advancements in the large area growth of two-dimensional (2D) materials [8] and demonstrations of high-performance field-effect transistors (FETs) based semiconducting TMDs such as monolayer MoS2 and WS2 through contact engineering [9,10], high-k gate dielectric integration [11][12][13], and aggressive channel length scaling [14,15] reinforces the technological relevance of 2D materials [16][17][18]. Furthermore, several reports have shown the benefits of using 2D FETs for digital [19][20][21], analog [22], and radio frequency electronics [23], neuromorphic computing [24][25][26][27], edge sensing [28,29], and hardware security [30][31][32] applications.…”

Ultrafast and Low-Power 2D Bi2O2Se Memristors for Neuromorphic Computing Applications

“…15,18 For example, Zhang et al reported a top-gated Bi 2 O 2 Se/Bi 2 SeO 5 transistor with sub-0.5 nm-equivalent-oxidethickness dielectrics via the ultraviolet-assisted intercalative oxidation. 13 Chen et al reported BP/Bi 2 O 2 Se van der Waals photodetectors with momentum-matching and band-alignment heterostructures to achieve high quantum efficiency (QE). 19 In terms of memristor, a three-terminal memristive device based on Bi 2 O 2 Se and HfO 2 has realized the function of short-term plasticity, long-term plasticity, and simulated "sleep-wake cycle autoregulation".…”

“…Layered 2D materials, such as transition-metal dichalcogenides (TMDs), black phosphorus (BP), graphene, and boron nitride (BN), have been showing the promising potential applications in memristors and artificial synapses, due to the excellent capabilities of ultrathin scaling, low switching voltage, high switching speed, and CMOS-compatible ultradense integration . More impressively, 2D bismuth oxyselenide (Bi 2 O 2 Se) is an emerging air-stable material platform with high mobility (>20000 cm 2 V –1 S –1 ), , and it can react to form a high-κ native oxide Bi 2 SeO 5 , , which makes it particularly favorable in the electronics industry . In recent years, Bi 2 O 2 Se has been widely studied in transistors, , photodetectors, gas sensors, and motion sensors because of the unique surface and crystal structure. , For example, Zhang et al reported a top-gated Bi 2 O 2 Se/Bi 2 SeO 5 transistor with sub-0.5 nm-equivalent-oxide-thickness dielectrics via the ultraviolet-assisted intercalative oxidation .…”

“…More impressively, 2D bismuth oxyselenide (Bi 2 O 2 Se) is an emerging air-stable material platform with high mobility (>20000 cm 2 V –1 S –1 ), , and it can react to form a high-κ native oxide Bi 2 SeO 5 , , which makes it particularly favorable in the electronics industry . In recent years, Bi 2 O 2 Se has been widely studied in transistors, , photodetectors, gas sensors, and motion sensors because of the unique surface and crystal structure. , For example, Zhang et al reported a top-gated Bi 2 O 2 Se/Bi 2 SeO 5 transistor with sub-0.5 nm-equivalent-oxide-thickness dielectrics via the ultraviolet-assisted intercalative oxidation . Chen et al reported BP/Bi 2 O 2 Se van der Waals photodetectors with momentum-matching and band-alignment heterostructures to achieve high quantum efficiency (QE) .…”

Liquid-Metal-Printed Ultrathin Oxides for Atomically Smooth 2D Material Heterostructures

“…Methods for depositing high- k dielectrics on 2D materials using seeding layers or surface functionalization in ALD have been reported, with varying success in dielectric and interface quality and preserving 2D material properties. ,,− In the recent few years, several other significant developments have been achieved in gate dielectric integration on 2D materials. ,− While promising 2D-material-based FETs with low subthreshold swings, small EOTs, and low gate current leakage levels had been achieved in some of these studies, several limitations remain. These include devices limited to back gates, , reliance on special substrates annealed at high temperatures >1000 °C, , hysteresis, − or applicable only to specific 2D semiconductors …”