Circuit Help

[retupmoc]

For my 3rd year lab i need to verify the Shockley equation by building the circuit shown on page 4 of the link below:

http://www.physics.gla.ac.uk/Physics3/Lab%20scripts/semiconductors.pdf

Can anyone explain to me how this circuit works? thanks

[retupmoc]

No one know, coz ive got to give a 5 min oral presentation describing how this circuit works before explaining my results and i really dont know where to start