Test

This manuscript “Quantum tunneling in two-dimensional van der Waals heterostructures and devices” by Fan, Sidi et al. summarizes information related to tunneling transport mechanism in 2D vdW heterostructures. The discussion and reasoning are also clear and concise to reveal the advantages and challenges of the 2D tunnel device. Discussion includes most of the significant research progresses in this area, some of the latest works, which provide insights for researchers to look into these signs of progress in a systematic manner. In general, this review summarized current works in an intriguing perspective and could appeal to researchers in nanomaterials and heterostructures.
Thus, I suggest its publication in SCIENCE CHINA Materials after minor revisions
1. In the introduction part, the review emphasized that “we comprehensively review quantum tunneling engineering in 2D vdW heterostructure from the fabrication, mechanism, and application points of view” on Page 3 (line 38). Thus, the authors should briefly discuss the assembly and integration method for heterostructures related to 2D materials.
2. Page 5 (Line 56) ~ page 6 (Line 10): Are the “graphene and hBN” parts necessary? It is not clear why authors need to discuss it. Thus, I suggest authors add one more sentence to explain why authors summarize properties of graphene, h-BN, and hBN part should be briefly discussed more or the authors should delete those parts.
3. Please make sure to define acronyms first before using them. For example, NDR (Line 13 – page 10), EMIM: TFSI (Line 52- page 27), etc.
4. The authors should add references for the below part:
- Page 11 (Line 45): two critical factors to evaluate a tunnel diode;
- Page 13 (Tunneling field-effect transistor): line 38, line 43, line 50;
- Page 28 (Line 20 + 52), Page 25 (Line 17): Esaki diodes based on 3D materials;
- Page 28 (Line 52): 3D materials with higher carrier concentration and higher mobility.
5. Page 24 (Line 24 + 29): Duel gate means dual-gate? This word needs to be revised.
6. For the 2D device applications section, is the “h-BN tunneling barrier assisted contact scheme in device” part necessary? Because this problem is briefly discussed in Conclusion and Challenges.
7. I suggest the authors change all figures to high-resolution figures.