Resistivity and Band Gap Measurement of semiconductor is a versatile and useful system for physics and basic electronics laboratories. Band Gap can be measured by using Four Probe Method. This is one of the widely used methods for measuring the Resistivity and Band Gap of semiconductors.

A collinear four-probe arrangement has been used. In this system, we provide the pressure contacts with sample to take quick measurement on different positions. The setup is equipped with display for simultaneous measurement of voltage & current.

Setup Consists Of:

n Four Probe Apparatus
n Oven
n Four probe assembly 
n Crystal
n Thermometer

Features:

n A complete setup for measuring the Resistivity and Band Gap

n Four individually spring loaded probe arrangement is provided

n Collinear and equally spaced probes
n The probes are mounted in a Teflon bush, which ensure a good electrical insulation between the

probes
n Sample-Germanium crystal

Scope of Learning:

n Resistivity of semiconductor by four-probe method.

n Determination of Energy Band Gap.

Technical Specifications :

Four probe experimental setup (1)

Voltmeter Display            :    31⁄2 digit, 7segment LED, auto polarity & decimal indication.

Current Display                :     31⁄2 digit, 7segment LED

Current Range                 : 0-20mA DC, 4mm socket

Input Voltage : 220V, 50Hz AC

Oven (1)

Ambient Temperature : 175° C

Oven Supply : Variable volts AC

Oven Connector : 3 Pin

Four probe arrangement (1)

Four probe                   : Spring type
Probe Spacing             : 2mm
Crystal                           : Ge Wafer, P type
Crystal Size                  : 10 x5 x 0.5mm approx

Resistivity                     : 1~ 10 ohm-cm Connection : 4mm safety socket

Sample crystal (Ge) (1)

Thermometer (1)

Type : Mercury
Temperature Range : 0-250° C

Least Count : 1° C
Length : 300mm approx