High current density 2D/3D MoS2/GaN Esaki tunnel diodes

Krishnamoorthy, Sriram; Lee, Edwin W.; Lee, Choong Hee; Zhang, Y.; McCulloch, William D.; Johnson, Jared M.; Hwang, Jinwoo; Wu, Yiying; Rajan, Siddharth

doi:10.1063/1.4966283

Cited by 70 publications

(58 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…9,10 Recent advances in the integration of 2D-layered materials with wide band gap group-III nitride semiconductors are exciting due to their variety of applications in high current tunnel diodes. [11][12][13] In this context, several efforts were made to grow GaN on closely lattice matched TMDs. Yamada et al reported the growth of GaN on bulk MoS 2 by plasma-enhanced molecular beam epitaxy (MBE).…”

mentioning

confidence: 99%

“…14 22,23 In spite of the smaller in-plane lattice mismatch (%0.8%) of GaN with MoS 2 , 15 the type-II heterojunction formed by them can be solely utilized for electronic devices. [11][12][13] In contrast, optoelectronic devices formed by 2D/ 3D heterojunctions require a type-I band alignment which can be realized by using the group III-nitride alloys with higher bandgap as a constituent semiconducting layer of the 2D/3D heterojunction. Thus, In x Al 1-x N with a low In composition (12%-18%) exhibiting higher bandgap (>4.5 eV) and lattice matched to the MoS 2 layer with high contrast of the refractive index (%30%) may be employed to achieve the type-I 2D/3D junction.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Type-I band alignment at MoS2/In0.15Al0.85N lattice matched heterojunction and realization of MoS2 quantum well

Tangi

Mishra

et al. 2017

Applied Physics Letters

View full text Add to dashboard Cite

The valence and conduction band offsets (VBO and CBO) at the semiconductor heterojunction are crucial parameters to design the active region of contemporary electronic and optoelectronic devices. In this report, to study the band alignment parameters at the In0.15Al0.85N/MoS2 lattice matched heterointerface, large area MoS2 single layers are chemical vapor deposited on molecular beam epitaxial grown In0.15Al0.85N films and vice versa. We grew InAlN having an in-plane lattice parameter closely matching with that of MoS2. We confirm that the grown MoS2 is a single layer from optical and structural analyses using micro-Raman spectroscopy and scanning transmission electron microscopy. The band offset parameters VBO and CBO at the In0.15Al0.85N/MoS2 heterojunction are determined to be 2.08 ± 0.15 and 0.60 ± 0.15 eV, respectively, with type-I band alignment using high-resolution x-ray photoelectron spectroscopy in conjunction with ultraviolet photoelectron spectroscopy. Furthermore, we design a MoS2 quantum well structure by growing an In0.15Al0.85N layer on MoS2/In0.15Al0.85N type-I heterostructure. By reducing the nitrogen plasma power and flow rate for the overgrown In0.15Al0.85N layers, we achieve unaltered structural properties and a reasonable preservation of photoluminescence intensity with a peak width of 70 meV for MoS2 quantum well (QW). The investigation provides a pathway towards realizing large area, air-stable, lattice matched, and eventual high efficiency In0.15Al0.85N/MoS2/In0.15Al0.85N QW-based light emitting devices.

show abstract

mentioning

confidence: 99%

mentioning

confidence: 99%

Type-I band alignment at MoS2/In0.15Al0.85N lattice matched heterojunction and realization of MoS2 quantum well

Tangi

Mishra

et al. 2017

Applied Physics Letters

View full text Add to dashboard Cite

show abstract

“…Further, we observe the ideality factor of GaN-MoS 2 diodes (1.5 < n < 2.0) is smaller than that of Si-MoS 2 diodes (2.0 < n < 3.5) because, in contrast to GaN, Si surface has a thin native oxide layer which degrades interface quality of 2D/3D junction (Figure 4d, Figure S3, Figure S15 in SI). 26,[44][45] Despite the differences in quality of the interface, the gate-tunability of rectification ratio maintains the same trend (Figure 4e, red plot) and the rectification ratio reaches a maximum when the MoS 2 is fully depleted suggesting a maximum in built-in potential and formation an n ++ /i junction. Likewise, a high asymmetry is observed in gate-dependent conductance (transfer characteristics) depending on whether the diode is forward biased (-V DS ) versus reverse biased (+V DS ).…”

Section: Resultsmentioning

confidence: 80%

“…7,23 Other approaches have been limited to exploiting lowpower operation or tunneling phenomena and photoresponse in two-terminal devices. [24][25][26][27][28][29] Overall, the advantage of using ultrathin 2D materials and exploiting their field tunability has not been systematically investigated and exploited.…”

Section: Introductionmentioning

confidence: 99%

Gate-Tunable Semiconductor Heterojunctions from 2D/3D van der Waals Interfaces

Miao

Liu

et al. 2020

Nano Lett.

View full text Add to dashboard Cite

Van der Waals (vdW) semiconductors are attractive for highly scaled devices and heterogeneous integration since they can be isolated into self-passivated, two-dimensional (2D) layers that enable superior electrostatic control. These attributes have led to numerous demonstrations of field-effect devices ranging from transistors to triodes. By exploiting the controlled, substitutional doping schemes in covalently-bonded, three-dimensional (3D) semiconductors and the passivated surfaces of 2D semiconductors, one can construct devices that can exceed performance metrics of "all-2D" vdW heterojunctions. Here, we demonstrate, 2D/3D semiconductor heterojunctions using MoS 2 as the prototypical 2D semiconductor laid upon Si and GaN as the 3D semiconductor layers. By tuning the Fermi levels in MoS 2 , we demonstrate devices that concurrently exhibit over seven orders of magnitude modulation in rectification ratios and conductance. Our results further suggest that the interface quality does not necessarily affect Fermi-level tuning at the junction opening up possibilities for novel 2D/3D heterojunction device architectures.

show abstract

“…2D materials can also be synthesized in a variety of compositions and structures, consequently resulting in novel properties at the interface that are not limited to the structural constraints in conventional interfaces, such as the choice of substrate and strain/defect control. Large area growth and/or transfer of 2D films have been extensively studied lately, most notably using metaldichalcogenides systems [1]. Here, we present the cross-sectional atomic scale imaging and analysis of GaSe 2D layered materials on GaN substrate using scanning transmission electron microscopy (STEM) [2].…”

mentioning

confidence: 99%

Atomic Scale Structure and Defects in 2D GaSe Films and Van der Waals Interface

et al. 2017

Self Cite

View full text Add to dashboard Cite

Recent advances in two-dimensional (2D) materials and interfaces have opened exciting new possibilities for realizing highly tunable electronic properties through innovative band gap engineering at the interface. 2D materials can also be synthesized in a variety of compositions and structures, consequently resulting in novel properties at the interface that are not limited to the structural constraints in conventional interfaces, such as the choice of substrate and strain/defect control. Large area growth and/or transfer of 2D films have been extensively studied lately, most notably using metaldichalcogenides systems [1]. Here, we present the cross-sectional atomic scale imaging and analysis of GaSe 2D layered materials on GaN substrate using scanning transmission electron microscopy (STEM) [2]. Our analysis shows important details of the atomic structure that can dictate the electronic properties of GaSe and a new atomic scale reconstruction at the GaSe/GaN van der Waals (vdW) interface that has not been observed in any conventional epitaxy. Our new findings may have important implications for controlling the atomic structure of 2D/3D interfaces for tuning of the electronic structure at the interface for novel device applications.GaSe can have multiple polytypes, and among them, the ε-type is a ~2 eV band gap semiconductor (Fig. 1a) and has been explored for applications in nonlinear optics, photovoltaics and photodetectors [3]. Our GaSe films were grown using a two-step temperature control in molecular beam epitaxy to ensure uniform film quality throughout the film structure. Cross-sectional TEM samples were prepared using focused ion beam, and examined using a C s -corrected FEI Titan STEM operated at 300 kV. Despite the single crystallinity indicated by X-ray diffraction (Fig. 1b), b domains are observed along with the intended, energetically more stable e-type domains, forming stacking faults and domain boundaries in between (Fig. 1c). These two polytypes differentiate through a 60° rotation of every other layer (Fig. 2). Rotational domain boundaries between the two types were also observed (indicated by the arrow). In addition, the 3 rd phase that had been previously unknown in literature was also found in between b and e phases (Fig. 1c). The results indicate that precise control of phase and growth defects will be crucial to achieve the desired properties of these 2D films. The interface between GaSe and GaN showed the most unexpected structure. The truncation layer of GaN still retained the GaN surface reconstruction pattern (1 x 1 reconstruction), and the surface was also "decorated" with an array of dumbbell atoms at the top (Fig. 2a). While it is difficult to directly identify the composition of the dumbbell atoms, we believe those may be Se atoms passivating the GaN surface. This indicates that the structure of the vdW interface can be significantly different from conventional epitaxial interfaces. The new structure at the interface, such as the ones found in this work, could also be used to tu...

show abstract

High current density 2D/3D MoS2/GaN Esaki tunnel diodes

Abstract: KEYWORDSMoS 2 , tunnel diode, GaN, 2D/3D heterojunction, interband tunneling.

Cited by 70 publications

References 37 publications

Type-I band alignment at MoS2/In0.15Al0.85N lattice matched heterojunction and realization of MoS2 quantum well

Type-I band alignment at MoS2/In0.15Al0.85N lattice matched heterojunction and realization of MoS2 quantum well

Gate-Tunable Semiconductor Heterojunctions from 2D/3D van der Waals Interfaces

Atomic Scale Structure and Defects in 2D GaSe Films and Van der Waals Interface

Contact Info

Product

Resources

About