Figure 3.

Optoelectronic response of the PD measured at a forward-bias of 5 V. (a) I_ph and (b) $ℛ$ and D* (inset) as a function of incident optical power P. The highest photosensitivity is exhibited at 100 K. (c) The I is directly proportional to the total carrier mobility μ where 1/μ = 1/μ_ph + 1/μ_imp. Above 200 K (shaded region) μ is dominated by electron-phonon scattering μ_ph, (μ_imp> μ_ph), while below this temperature, μ is largely determined by impurity scattering μ_imp (μ_ph> μ_imp). (d) $ℛ$ in the forward-bias regime at 300 K. The inset shows D* versus V_DS, which also shows that saturation is reached for V_DS> 2.25 V.