A \(\text{p-n}\) photodiode is fabricated from a semiconductor with a bandgap of \(2.8~\text{eV}.\) The energy of the incident photon with a wavelength of \(6000~\text{nm}\) is:
1. \(0.207~\text{eV}\)
2. \(0.270~\text{eV}\)
3. \(0.027~\text{eV}\)
4. \(0.072~\text{eV}\)

The number of silicon atoms per \(\text m^3\) is  \(5 × 10^{28}.\) This is doped simultaneously with \(5 × 10^{22}\) atoms per \(\text m^3\) of Arsenic and \(5 × 10^{20}\) per \(\text m^3\) atoms of Indium. The number of holes is:
(given that \(n_{i} = 1 . 5 \times 10^{16} ~\text m^{- 3}\))
1. \(4.51\times 10^{9}\)
2. \(4.99\times 10^{22}\)
3. \(1.56\times 10^{22}\)
4. \(3.33\times 10^{23}\)