$5\mathrm{.}17$ A Si $n^{+}p$ junction has an acceptor doping of $2{10}^{-1}c{m}_b$ on the p side and sectional area of ${10}^{-2}c{m}^2.$ If majority carrier lifetime is $10$ ns and correp? diffusion coefficient is $400c\frac{m^2}{sec},$ estimate the current density underat bias of $0\mathrm{.}3$ V at $300$ K temperature$\mathrm{.}5\mathrm{.}17$ A Si $n^{+}p$ junction has an acceptor doping of $2{10}^{-1}c{m}_b$ on the p side and sectional area of ${10}^{-2}c{m}^2.$ If majority carrier lifetime is $10$ ns and correp? diffusion coefficient is $400c\frac{m^2}{sec},$ estimate the current density underat bias of $0\mathrm{.}3$ V at $300$ K temperature.