A p+-n junction is formed in an n-type substrate with ND=1015cm-3. If the junction contains 1015 cm-3 generation-recombination centers located 0.02 eV above the intrinsic Fermi level of silicon with σn= σp= 10-15cm2 (Vth=107cm2), calculate the generation and recombination current at -0.5 V.
A p+-n junction is formed in an n-type substrate with ND=1015cm-3. If the junction contains 1015...
Consider silicon at a temperature of 300 [K], and a donor concentration ND = 4·1015 [cm-3]. The thermal equilibrium recombination rate is RP0=1·1011 [cm-3 s-1 ]. A uniform generation rate by illumination produces an excess-carrier concentration of on δn= δp=1·1014 [cm-3 ]. Note that at a temperature of 300 [K], the commonly accepted value for the intrinsic carrier concentration of silicon is ni = 1.5·1010 [cm-3] A) By what factor does the total recombination rate RP increase under illumination with respect to thermal equilibrium, RP/RP0 ?
B2 Consider a diode formed by making a p-n junction structure in a silicon sample as shown in Fig. B2. nt laver p-type Si Fig. B2 (a). If the dopant concentrations of the n layer and the p-type silicon are 6x101" cm and 8x10 cm respectively, calculate the built-in potential of the p-n junction at room temperature (300 K) 15 (3 marks) (b). Due to overheating of the silicon sample, the diode has an operation temperature of 200 °C and...
Assume a p-n step junction in silicon wi concentration of 2x1016,c? and the n-type material doped at 3X10-s,cm3 The intrinsic carrier density is 1.25X101°/cm and all dopants are fully ionized Assume that the effective density of states for silicon is 3.3x10 cm3 for the conduction band and 1.75x101 cm for the valence band. Assume that the temperature is 300K and silicon relative permittivity of 11.7 a. Compute the hole concentration on the n-side and electron concentration th the p-type material...
3. A silicon step junction has uniform impurity doping concentrations of N. 5 x 1015 cm-3 and Nd = 1 x 1015 cm-, and a cross-sectional area of A-|0-4 cm2. Let tao -0.4 s and tpo 0.1 us. Consider the geometry in Figure.Calculate (a) the ideal reverse saturation current due to holes, (b) the ideal reverse saturation current due to electrons, (c) the hole concentration at a, if V V and (d) the electron current at x = x" +...
Biased Sip-n junction A Si p-n junction with area of 0.001 cm* is formed with an acceptor concentration of Na 1x1015 cm3 on the p-side and a donor concentration of Na- 1x10" cmon the n-side. Calculate at 300 K (a) the diffusion voltage VD (b) the space charge width at equilibrium and with zero bias (c) the current with forward bias of 0.5 eV. Assume that the current is diffusion dominated. The electron and hole mobilities are ln-1500 cm2/(Vs) and...
Consider a junction between highly-doped n-type Si (n+ doping of 6*1018cm-3 and weakly doped n-Type Si n+ doping of 1*1015cm-3) . Plot the bands and Fermi levels. Now do the same assuming the doping is graded over the distance L.
Problem 2. A silicon NPN bipolar transistor has the following specifications: Emitter: N+: ND =1018 cm-3 , base: p-type, NA=1015 cm-3, collector: N-type, ND=5x1015 cm-3 . 1. Draw the energy band diagram of the transistor at thermal equilibrium, 2. If the transistor is biased at Normal Active Mode, emitter-base junction forward biased with 1 V, and collector-base junction is reverse biased with 4V, draw the energy band diagram.
5) A Si solar cell with junction cross sectional dimensions 2 cm ×2 cmis formed with Na 1018 cm3 on the p side and Nd 1018cm3 on the n side. It is operated at a temperature of 300 K and τn-tp-1 μ. a) Using the mobilities on the equation sheet, calculate the dark saturation current. b) An intrinsic region of thickness 200 μm is sandwiched between the p and n regions in order to enhance the active volume of the...
Consider an abrupt p-n junction formed by two steps; an entire silicon sample was first doped with 1.0E+15 cm-3 acceptors (step I), and then a half of the sample was doped with 2.0E+15 cm-3 donors at room temperature (step II). a. Calculate the Fermi levels on each side of the junction with respect to Ei. Use the Special Conditions to find the concentrations. b. Calculate the contact potential. c. Calculate the ratio , Xpo/Xno
Calculate (a) The junction depth xy and the total amount of dopant into p-type substrate with a bulk concentration CB of 5 * 1015 cm" after phosphorous pre deposition at 1000 °C for an hour (b) The junction depth xy of the sample in (a) after drive-in diffusion at 1100 "C for unction depth , of the sample in (o) after drive-in diflsion t 110 C for 3 hours.