Subject: Physical Chemistry · Chapter: Solid State Chemistry · Topic: Band Theory · Exam: CSIR-NET 2012 · Marks: 2 · Difficulty: Hard
The wavelength and the spectral region for a single electron transfer across the band gap in a semi conductor $\left(E_{x}-1.98 \times 10^{-19}\right)$ are $\left[h=6.626 \times 10^{-34}\,\mathrm{Js}, c=3 \times 10^{8}\,\mathrm{m\,s^{-1}}\right]$
(a)1000 nm, UV
(b)1000 nm, IR
(c)500 nm, visible
(d)500 nm, FAR IR
Answer
Answer (as printed): B
Explanation
$\lambda=\dfrac{hc}{E}$ = 1003.9 $\times 10^{-9}$ m = 1003.9 nm. This wavelength lies in the IR region.