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Q3 A rectangular slab of silicon is doped with 1022 m³ Boron (B) atoms. The intrinsic carrier concentration n, in silicon at 300K is 1.5x10¹6 m³ and it varies with temperature as T3/2exp(-Eg/2kT), where Eg-1.1eV is the bandgap energy, T is the absolute temperaturen K and k is Boltzmann's constant. The silicon slab is 6 um long with a rectangular cross section of 2 µm 2 (1 μm x 2 μm). Assume kT-0.026 eV and kT/q-0.026 V. Assume that the electron mobility is ue 0.04 m²/Vs and that the hole mobility is un=0.02 m²/Vs.
Calculate the resistance of the slab described above at 300K and 360K If 5x1022 m3 Gallium (Ga) atoms were added to this sample calculate the majority and minority carrier concentrations last) 300 K and state the type of carrier (electron or hole). State whether the same is n-type, p-type or fully compensated. (4 marks) (vi) Calculate the current density and the current through the original sample of question i) if 5 V is dropped along the length of this silicon slab at 300 K. Which type of carrier: electron or hole contributes most of the total current? (5 marks) vii) Calculate the Fermi Level, Er, of the original sample of question i) relative to the valence band edge Ev. (4 marks)