1)Built-in voltage for a Si p-n junction is tested to be 0.6 V, NA = 2 X 10^15 cm^-3 on p side. Find ND on n side. (Assume ni = 1 x 10^10 cm^-3; and k*T/q= 0.026 V)
2)An ideal p-n junction diode has saturation current Is = 3e-15 A. Calculate the diode current when a (a) forward bias of 0.9 V is applied and (b) a reverse bias of -0.9 V is applied. Hint: at room temperature (k*T/q = 0.026 V)
3)A pn-junction is uniformly doped and has dopant concentration of NA = 4 x10^16 cm^-3 in the pregion at 300K. At zero bias, 20% of the total space charge region (W) is extended in the pregion. Calculate Vbi, ND, W, xn and xp. Given that ni = 1.8 x 10^6 cm-3 and e=1.16 x 10^-12 F/cm.