Limits...
Temperature-triggered chemical switching growth of in-plane and vertically stacked graphene-boron nitride heterostructures.

Gao T, Song X, Du H, Nie Y, Chen Y, Ji Q, Sun J, Yang Y, Zhang Y, Liu Z - Nat Commun (2015)

Bottom Line: Here, via chemical vapour deposition and using benzoic acid precursor, we have achieved the selective growth of h-BN-G and G/h-BN through a temperature-triggered switching reaction.The present work demonstrates the chemical designability of growth process for controlled synthesis of graphene and h-BN heterostructures.With practical scalability, high uniformity and quality, our approach will promote the development of graphene-based electronics and optoelectronics.

View Article: PubMed Central - PubMed

Affiliation: Center for Nanochemistry (CNC), Beijing Science and Engineering Center for Low-Dimensional Carbon Materials, Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.

ABSTRACT
In-plane and vertically stacked heterostructures of graphene and hexagonal boron nitride (h-BN-G and G/h-BN, respectively) are both recent focuses of graphene research. However, targeted synthesis of either heterostructure remains a challenge. Here, via chemical vapour deposition and using benzoic acid precursor, we have achieved the selective growth of h-BN-G and G/h-BN through a temperature-triggered switching reaction. The perfect in-plane h-BN-G is characterized by scanning tunnelling microscopy (STM), showing atomically patched graphene and h-BN with typical zigzag edges. In contrast, the vertical alignment of G/h-BN is confirmed by unique lattice-mismatch-induced moiré patterns in high-resolution STM images, and two sets of aligned selected area electron diffraction spots, both suggesting a van der Waals epitaxial mechanism. The present work demonstrates the chemical designability of growth process for controlled synthesis of graphene and h-BN heterostructures. With practical scalability, high uniformity and quality, our approach will promote the development of graphene-based electronics and optoelectronics.

No MeSH data available.


Related in: MedlinePlus

Stacking geometry of G/h-BN.(a) Large-scale TEM image of graphene islands on h-BN. (b,c) Magnified TEM images of (a) along the film edges. The scale bars in a–c are 1 μm, 20 and 2 nm, respectively. (d) SAED data demonstrating the aligned configuration of G/h-BN with the close-up views of the diffraction spots marked by circles. (e) Intensity profile along the blue line in (d) identifying the graphene and h-BN diffraction spots. (f) Stacking registry survey of G/h-BN, suggesting a well-aligned vertical stacking geometry. (g,h) SEM images of h-BN partially and fully covered by graphene, respectively. (i) Photograph of the wafer-scale G/h-BN film transferred onto SiO2/Si substrate with an OM image as an inset. (j) SEM image of large graphene domain grown on h-BN. The scale bars in g–j are 1, 2, 20 and 5 μm, respectively. (k) Optical microscope image of graphene back-gated field effect transistor (FET) fabricated on 300 nm SiO2/Si. The scale bar in k is 20 μm. (l) Device drain current (Ids) and resistance (R) versus gate voltage (Vgate).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4403442&req=5

f5: Stacking geometry of G/h-BN.(a) Large-scale TEM image of graphene islands on h-BN. (b,c) Magnified TEM images of (a) along the film edges. The scale bars in a–c are 1 μm, 20 and 2 nm, respectively. (d) SAED data demonstrating the aligned configuration of G/h-BN with the close-up views of the diffraction spots marked by circles. (e) Intensity profile along the blue line in (d) identifying the graphene and h-BN diffraction spots. (f) Stacking registry survey of G/h-BN, suggesting a well-aligned vertical stacking geometry. (g,h) SEM images of h-BN partially and fully covered by graphene, respectively. (i) Photograph of the wafer-scale G/h-BN film transferred onto SiO2/Si substrate with an OM image as an inset. (j) SEM image of large graphene domain grown on h-BN. The scale bars in g–j are 1, 2, 20 and 5 μm, respectively. (k) Optical microscope image of graphene back-gated field effect transistor (FET) fabricated on 300 nm SiO2/Si. The scale bar in k is 20 μm. (l) Device drain current (Ids) and resistance (R) versus gate voltage (Vgate).

Mentions: To confirm the stacking registry and twist angle between graphene and h-BN in the G/h-BN film on a large scale, high-resolution transmission electron microscopy (HR-TEM) combined with selected area electron diffraction (SAED) measurements were conducted. The TEM image of G/h-BN with submonolayer graphene coverage in Fig. 5a depicts two discrete graphene flakes showing higher contrast than the underlying h-BN. Figure 5b displays the TEM view of the G/h-BN film with full graphene coverage, where the edges of the sheet breakage allow for the direct identification of a bilayer. The HR-TEM image in Fig. 5c further confirms the bilayer nature and uniformity of G/h-BN. Shown in Fig. 5d is the SAED measurement of G/h-BN heterostructure, which exhibits a similar sixfold diffraction pattern. Close-up views of the regions identified by blue circles show two separated spots along the radial direction. The outer spot should correspond to the graphene lattice due to its relatively shorter lattice constant of 0.246 nm. Meanwhile, the intensity profiles along the radial direction of the SAED spots are plotted in Fig. 5e, where the peaks marked with blue arrows yield two components after Gaussian fitting. The ratio of the distance between the outer and inner peaks, representing the lattice parameter ratio between graphene and h-BN, is calculated to be 1.0166, consistent with the theoretical value (0.246/0.250=1.016).


Temperature-triggered chemical switching growth of in-plane and vertically stacked graphene-boron nitride heterostructures.

Gao T, Song X, Du H, Nie Y, Chen Y, Ji Q, Sun J, Yang Y, Zhang Y, Liu Z - Nat Commun (2015)

Stacking geometry of G/h-BN.(a) Large-scale TEM image of graphene islands on h-BN. (b,c) Magnified TEM images of (a) along the film edges. The scale bars in a–c are 1 μm, 20 and 2 nm, respectively. (d) SAED data demonstrating the aligned configuration of G/h-BN with the close-up views of the diffraction spots marked by circles. (e) Intensity profile along the blue line in (d) identifying the graphene and h-BN diffraction spots. (f) Stacking registry survey of G/h-BN, suggesting a well-aligned vertical stacking geometry. (g,h) SEM images of h-BN partially and fully covered by graphene, respectively. (i) Photograph of the wafer-scale G/h-BN film transferred onto SiO2/Si substrate with an OM image as an inset. (j) SEM image of large graphene domain grown on h-BN. The scale bars in g–j are 1, 2, 20 and 5 μm, respectively. (k) Optical microscope image of graphene back-gated field effect transistor (FET) fabricated on 300 nm SiO2/Si. The scale bar in k is 20 μm. (l) Device drain current (Ids) and resistance (R) versus gate voltage (Vgate).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4403442&req=5

f5: Stacking geometry of G/h-BN.(a) Large-scale TEM image of graphene islands on h-BN. (b,c) Magnified TEM images of (a) along the film edges. The scale bars in a–c are 1 μm, 20 and 2 nm, respectively. (d) SAED data demonstrating the aligned configuration of G/h-BN with the close-up views of the diffraction spots marked by circles. (e) Intensity profile along the blue line in (d) identifying the graphene and h-BN diffraction spots. (f) Stacking registry survey of G/h-BN, suggesting a well-aligned vertical stacking geometry. (g,h) SEM images of h-BN partially and fully covered by graphene, respectively. (i) Photograph of the wafer-scale G/h-BN film transferred onto SiO2/Si substrate with an OM image as an inset. (j) SEM image of large graphene domain grown on h-BN. The scale bars in g–j are 1, 2, 20 and 5 μm, respectively. (k) Optical microscope image of graphene back-gated field effect transistor (FET) fabricated on 300 nm SiO2/Si. The scale bar in k is 20 μm. (l) Device drain current (Ids) and resistance (R) versus gate voltage (Vgate).
Mentions: To confirm the stacking registry and twist angle between graphene and h-BN in the G/h-BN film on a large scale, high-resolution transmission electron microscopy (HR-TEM) combined with selected area electron diffraction (SAED) measurements were conducted. The TEM image of G/h-BN with submonolayer graphene coverage in Fig. 5a depicts two discrete graphene flakes showing higher contrast than the underlying h-BN. Figure 5b displays the TEM view of the G/h-BN film with full graphene coverage, where the edges of the sheet breakage allow for the direct identification of a bilayer. The HR-TEM image in Fig. 5c further confirms the bilayer nature and uniformity of G/h-BN. Shown in Fig. 5d is the SAED measurement of G/h-BN heterostructure, which exhibits a similar sixfold diffraction pattern. Close-up views of the regions identified by blue circles show two separated spots along the radial direction. The outer spot should correspond to the graphene lattice due to its relatively shorter lattice constant of 0.246 nm. Meanwhile, the intensity profiles along the radial direction of the SAED spots are plotted in Fig. 5e, where the peaks marked with blue arrows yield two components after Gaussian fitting. The ratio of the distance between the outer and inner peaks, representing the lattice parameter ratio between graphene and h-BN, is calculated to be 1.0166, consistent with the theoretical value (0.246/0.250=1.016).

Bottom Line: Here, via chemical vapour deposition and using benzoic acid precursor, we have achieved the selective growth of h-BN-G and G/h-BN through a temperature-triggered switching reaction.The present work demonstrates the chemical designability of growth process for controlled synthesis of graphene and h-BN heterostructures.With practical scalability, high uniformity and quality, our approach will promote the development of graphene-based electronics and optoelectronics.

View Article: PubMed Central - PubMed

Affiliation: Center for Nanochemistry (CNC), Beijing Science and Engineering Center for Low-Dimensional Carbon Materials, Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.

ABSTRACT
In-plane and vertically stacked heterostructures of graphene and hexagonal boron nitride (h-BN-G and G/h-BN, respectively) are both recent focuses of graphene research. However, targeted synthesis of either heterostructure remains a challenge. Here, via chemical vapour deposition and using benzoic acid precursor, we have achieved the selective growth of h-BN-G and G/h-BN through a temperature-triggered switching reaction. The perfect in-plane h-BN-G is characterized by scanning tunnelling microscopy (STM), showing atomically patched graphene and h-BN with typical zigzag edges. In contrast, the vertical alignment of G/h-BN is confirmed by unique lattice-mismatch-induced moiré patterns in high-resolution STM images, and two sets of aligned selected area electron diffraction spots, both suggesting a van der Waals epitaxial mechanism. The present work demonstrates the chemical designability of growth process for controlled synthesis of graphene and h-BN heterostructures. With practical scalability, high uniformity and quality, our approach will promote the development of graphene-based electronics and optoelectronics.

No MeSH data available.


Related in: MedlinePlus