Pn - junction diode experiment - varying heat

[shreyazaveri]

Homework Statement

This isn't exactly a problem, but I need help with an experiment. I've got to design an experiment to show a) the variation of voltage with a diode when the diode is in forward bias
b) The variation of current (i think) with heat, keeping voltage constant.
The thing is I'm not sure how to design the part 'B' experiment, and I also have to predict the graph that will be generated from the output.

Homework Equations

I'm pretty sure I've got to use I = Io exp (eV/2kt) where
I = Current,
Io = Max current at absolute zero,
e= charge on an electron
V= voltage
k = Boltzmann's Constant
t = Temperature in Kelvin.

The Attempt at a Solution

For a)
I set up the circuit with a 1.5 V D.C supply connected in series with a rheostat, milliammeter and the diode in forward bias and a voltmeter in parallel with the diode. I varied current and measured the corresponding voltage (making sure to keep the current low, <50 milliamps)
I had to ln the equation to make the ln I - V graph linear (for experiment a)

ln I = Ln Io + (eV/2kT)
with Ln I on the Y axis and V on the X.
This made a linear graph and allowed me to calculate the value of e from the gradient, compare it to the standard and derive the percentage error of my experiment a.

I need to do something similar with b)

Any help will be greatly appreciated.
Also, this is my first post so I'm really sorry for any faux-pas.

 

[anathema]

It sounds like you are conducting an experiment to investigate the behavior of a diode in both forward bias and with varying heat. For part b), you will need to design a setup that can control the temperature of the diode while keeping the voltage constant. One approach could be to use a heating element, such as a heating pad or a hot plate, to heat the diode while using a voltage regulator to maintain a constant voltage. You can then measure the current at different temperatures and plot it against the temperature to see how it varies.

As for predicting the graph, it will depend on the specific diode you are using and its characteristics. However, you can expect to see an increase in current with increasing temperature, as the heat will cause more carriers to be available for conduction. The exact shape of the graph will depend on the specific diode and the temperature range you are investigating.

I hope this helps and good luck with your experiment! Let us know if you have any further questions.