Calculate the open-circuit voltage of a silicon pn junction solar cell.
Consider a silicon pn junction at T=300 \mathrm{~K} with the following parameters:
\begin{array}{ll}N_{a}=5 \times 10^{18} \mathrm{~cm}^{-3} & N_{d}=10^{16} \mathrm{~cm}^{-3} \\D_{n}=25 \mathrm{~cm}^{2} / \mathrm{s} & D_{p}=10 \mathrm{~cm}^{2} / \mathrm{s} \\\tau_{n 0}=5 \times 10^{-7} \mathrm{~s} & \tau_{p 0}=10^{-7} \mathrm{~s}\end{array}
Let the photocurrent density be J_{L}=I_{L} / A=15 \mathrm{~mA} / \mathrm{cm}^{2}.