give the v-I characteristic of a pn junction diode?

Question

with circuit diagram

Answer 1

I = Io [ 1 - e^(v/(nV))]

here I = current through the pn juction diode
Io = reverse saturation current
v = voltage across the diode
n = a constant, value ranges from 1 to 2. It depend on the fabrication of the diode.
V = thermal voltage = kT/q
T = temperature in kelvin scale
k = Boltzman constant
q = electron charge = -1.6 X 10 ^ -19 C

the circuit diagram is very simple, draw a diode is series with a voltage source. Hope this can help. Check any microelectronics book for more information. I recommend " Microelectronic Circuits by Sedra/Smith"

Answer 2

this is because the solar cell does not draw current but supplies the same to the load,.. thts y drawn in the 4th quadrant

Answer 3

go and read any semiconductor text book.

Answer 4

I have the idea.But no way to sketch.Sorry....