GATE EC 2022 Set 1 Q46 — Electronic Devices

A $p-$type semiconductor with zero electric field is under illumination (low level injection) in steady state condition. Excess minority carrier density is zero at $x = \pm 2l_{n},$ where $l_{n} = 10 ^{-4} \; \text{cm}$ is the diffusion length of electrons. Assume electronic charge, $q = – 1.6 \times 10^{-19} \; \text{C.}$ The profiles of photo-generation rate of carriers and the recombination rate of excess minority carriers $(R)$ are shown. Under these conditions, the magnitude of the current density due to the photo-generated electrons at $x = + 2l_{n}$ is ______________ $\text{mA/cm}^{2}$ (rounded off to two decimal places).