Tungsten diselenide (WSe2) is an emerging material for electronic applications. Answer the following questions to understand...

    

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Tungsten diselenide (WSe2) is an emerging material for electronic applications. Answer the following questions to understand what makes it so interesting. (2 + 2 + 2+ 1+ 2 +2 + 2 +1 +2 16 marks) (a) What percentage of ionic character does this material possess? (b) What type of coordination would the cation be expected to be in? (c) What type of coordination would you expect for the anion? (d) Using the VESTA model provided show the representative lattice structure at a variety of angles, explicitly showing the d-spacing. (e) Comment on whether the Pauling rules apply to WSe2? (f) What Bravais lattice does WSe2 form and what are its unit lattice parameters? (g) Does the WSe2 structure relate more strongly to single or double layered clays? Explain your reasoning. (h) Under what structural conditions would you expect WSe2 to exhibit electrical properties that are comparable to graphene? (i) Noting that the optical bandgap of graphene is zero, explain why WSe2 is a potentially lucrative material for applications such as light emitting diodes, whilst graphene is largely useful simply as a conductor. Tungsten diselenide (WSe2) is an emerging material for electronic applications. Answer the following questions to understand what makes it so interesting. (2 + 2 + 2+ 1+ 2 +2 + 2 +1 +2 16 marks) (a) What percentage of ionic character does this material possess? (b) What type of coordination would the cation be expected to be in? (c) What type of coordination would you expect for the anion? (d) Using the VESTA model provided show the representative lattice structure at a variety of angles, explicitly showing the d-spacing. (e) Comment on whether the Pauling rules apply to WSe2? (f) What Bravais lattice does WSe2 form and what are its unit lattice parameters? (g) Does the WSe2 structure relate more strongly to single or double layered clays? Explain your reasoning. (h) Under what structural conditions would you expect WSe2 to exhibit electrical properties that are comparable to graphene? (i) Noting that the optical bandgap of graphene is zero, explain why WSe2 is a potentially lucrative material for applications such as light emitting diodes, whilst graphene is largely useful simply as a conductor.

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a WSe2 possesses approximately 50 ionic character b The cation in WSe2 is expected to be in octahedr... View the full answer