Semiconductor physics
Which value is closest to the lattice constant of crystalline silicon?
- AAbout 0.543 nm
- BAbout 0.054 nm
- CAbout 5.43 nm
Show answer and explanation
Answer: A. About 0.543 nm
Silicon has the diamond structure, and the edge of its cubic unit cell (the lattice constant) is about 0.543 nm (5.43 Å). Each unit cell contains eight atoms, giving an atomic density of about 5×10²² cm⁻³.
- A. Correct. The lattice constant is about 0.543 nm.
- B. About 0.054 nm is smaller than an atom; it is an order of magnitude too small.
- C. About 5.43 nm is an order of magnitude too large; 5.43 is the value in ångströms.