A p-n photodiode is made of a material with a band gap of 2.0 eV. The minimum frequency of the radiation that can be absorbed by the material is nearly

10 x 10¹⁴ Hz

5 x 10¹⁴ Hz

1 x 10¹⁴ Hz

20 x 10¹⁴ Hz

Answer

5 x 10¹⁴ Hz

the p-n photodiode is a semiconductor diode that produces a significant current when illuminated. It is reversed biased but is operated below the breakdown voltage.
Energy of radiation = band gap energy
ie, hv = 2.0 eV
or v= 2.0 x 1.6 x 10^-19 / 6.6 x 10^-34 = 5 x 10¹⁴ Hz