A Si pn-junction, in the p-region NA= 107 cm, Dn = 39 cm/sec, tn=1 psec and...

 

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A Si pn-junction, in the p-region NA= 10¹7 cm³, Dn = 39 cm²/sec, tn=1 psec and in the n-region No = 5x10¹ cm³, D₂=12 cm²/sec, tp = 1 psec .The cross section area A = 20μm x 50μm and T=300K. a) Calculate the junction built-in voltage Vo. b) If VF = 0.8 Vo : (i) calculate the excess carriers concentration at the edges of the depletion region. (ii) calculate the current due to holes Ip (iii) calculate the current due to electrons In. c) If this junction is to be used as the emitter- base of a PNP BJT calculate the injection efficiency YE d) If this junction is to be used as the emitter-base of a NPN BJT with the n-region as the emitter, calculate the injection efficiency YE e) Should the BJT be a good PNP or NPN?. Explain your choice. M . A Si pn-junction, in the p-region NA= 10¹7 cm³, Dn = 39 cm²/sec, tn=1 psec and in the n-region No = 5x10¹ cm³, D₂=12 cm²/sec, tp = 1 psec .The cross section area A = 20μm x 50μm and T=300K. a) Calculate the junction built-in voltage Vo. b) If VF = 0.8 Vo : (i) calculate the excess carriers concentration at the edges of the depletion region. (ii) calculate the current due to holes Ip (iii) calculate the current due to electrons In. c) If this junction is to be used as the emitter- base of a PNP BJT calculate the injection efficiency YE d) If this junction is to be used as the emitter-base of a NPN BJT with the n-region as the emitter, calculate the injection efficiency YE e) Should the BJT be a good PNP or NPN?. Explain your choice. M .

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Calculate the junction builtin voltage Vo The potential drop across the depletion region is given by Vd klnNpNi At thermal equilibrium Ni NoeeVkT1 Np NAeeVkT Therefore Vd klnNAeeVkTNoeeVkT1 The potent... View the full answer