Energy Band-Gap And Diffusion Potential OF P-N Junctions

This is an advanced level experiment to be performed on commercially available diodes viz. germanium or silicon diodes, various types of LED's and also on the base emitter/ collector-base junctions of a transistor. The results of the experiments not only give the device characteristics but also provide an insight into the properties of the materials used in the fabrication of the junction.  In the set-up, all the necessary instrumentation is integrated as a result of which a minimum of external connections need to be made by the user. Supplied
W/o DSO/CRO.

The Instrument consists of the following

Study of P-N Junction

(i) 3½ digit DPM for current/temperature measurements

(ii) 3½ digit DPM for bias voltage/junction voltage

(iii) Two parts to connect the diode 

(iv) Two fixed frequency oscillators (5KHz & 20KHz) with the same output (200 mV).

Set of samples
(i) Transistor BC109 (base-emitter)-Si

(ii) Transistor AC126 (base-emitter)-Ge

(iii) Diode 1N 5408/1N 4007-Si

Fast temperature controlled oven with sensor

Following experiments can be performed.

(I) Reverse saturation current I and material constant h

(ii) Temperature coefficient of junction voltage dV/dt 0

(iii) Energy band-gap VG

(iv) Junction capacitance