2. A GaAs semiconductor at T 300 K is uniformly doped with NA 1016 cm3 and...
A “thin” slab (thickness d << 1/α, where α is the absorption coefficient) of GaAs semiconductor at T = 300 K is uniformly doped with NA = 1016 cm-3 and ND = 0. The GaAs is illuminated with a light source at t = 0 s, resulting in a uniform generation rate of electron hole pairs g’ = 1020 cm-3s-1 through-out the slab of GaAs. The electric field is zero. a) Give the analytic expression for the excess-carrier concentration δn(t)...
PartYour AnswerCorrect AnswerToleranceMarks Comment 4.0 1% 1.00 Correct Total: 1.0 A p-type semiconductor, doped to a uniform concentration of 5.3 x 1015 cm-3, is exposed to a light source which generates electron-hole pairs everywhere in the semiconductor at a rate of 8.8 x 1020 cm-3s-1. The excess carrier lifetime is 0.1 us and the intrinsic carrier concentration is 6.9 x 109 cm-3. Which of the following most accurately gives the hole concentration at steady state? Assume band-to-band transition. Please choose...
QUESTION TWO (9 marks total) (a) An n-type semiconductor has a uniform excess minority carrier concentration of 5 x 1015 cm3 and minority carrier lifetime T 1.5 us in the bulk, and minority carrier lifetime Ts 0.2 us at the surface. D 10 cm2/s. Assuming zero applied electric field and low-level injection: Determine the steady-state excess carrier concentration at the surface What is the generation rate? Enter calculated values in the boxes below (5 marks) (Hint: steady-state means time-invariant; that...
Assuming complete ionization, determine the equilibrium electron and hole concentrations inside a uniformly doped Si under the following conditions V. Assuming complete ionization, determine the equilibrium electron and hole concentration inside a uniformly doped Si under the following conditions: a) T= 200 K, N,-9 x 1015 /cm, ND-1016 /cm3 b) T= 450 K, N,-0, ND-1014 /cm3 V. Assuming complete ionization, determine the equilibrium electron and hole concentration inside a uniformly doped Si under the following conditions: a) T= 200 K,...
3. (1 charge 5-poits) A semiconductor is uniformly illuminated, and generated 1015/cm3 excess carrier. If we turn off the source of illumination, a) what will be the concentration of charge carrier at t 1 us and at 10us after the illumination turned off. The carrier life time τ-10's b) ) calculate the conductivity of the sample before turning the light off, and after 10 us 3. (1 charge 5-poits) A semiconductor is uniformly illuminated, and generated 1015/cm3 excess carrier. If...
A uniformly acceptor-doped silicon wafer at room temperature is illuminated with light at t = 0. Assuming NA = 1016/cm3 , n = 10-6 sec, and a light-induced creation of 1017 electrons and holes per cm3 -sec throughout the semiconductor, what is the simplified MCDE?
3. A silicon npn bipolar transistor is uniformly doped and biased in the forward active region with the base-collector junction reverse biased by 2.5 V. The metallurgical base width is 1.5 μm. The emitter, base collector doping concentrations are 5 × 1017, 1016, 2 × 1015 cm-3 respectively. a. At T-300 K, calculate the base-emitter voltage at which the minority carrier electron concentration at x-0 is 20% of the majority carrier hole concentration. At this voltage calculate the minority carrier...
Semiconductor Physics: A semiconductor has a intrinsic concentration of 1010 cm-3 and has donor impurity concentration of 1015 cm-3. Light is shined (uniformly) upon the sample generating 5*1019 electron-hole pairs.cm-3s-1 with a minority carrier lifetime of 10-6 s. What is the net electron-hole recombination rate? I think at steady state, the electron-hole recombination rate is the same as the generation rate. But the current circumstances of the question make me doubt that assumption or conclusion (the question is 4 marks).
Problem 3 (25 points) Consider a silicon pn junction at T - 300 K, NA- 1016 cm3, ND-5x1016 cm-3. The minority carrier lifetimes are τα , τ,-1 us. The junction is forward biased with Va-0.5V The minority carrier diffusion coefficients are D 25 cm/s, Da- 10 cm2/s n,1.5x1010 cm3 kT 0.0267 Depletion region p-type n-type a) (5 points) Calculate the excess electron concentration as a function of x in the p-side (see the figure above) b) (10 points) Calculate the...
Assume that a uniform p-type region of silicon with length L-10 μm, μη-1400 cm2/V-s, and lifetime t 1 us at T 300 K is uniformly illuminated by photon flux G 1019/cm2s. Assume that that all carriers are extracted at x-L (such that Δη-0), while An-1014 /cm3 at x 0. Assume that Po An everwhere. Now consider the system after reaching a steady state. 2. Write down the simplest form of the minority carrier diffusion equation that accurately describes its behavior....