Resistivity of Semiconductors by Four Probe Method at Different Temperatures and Determination of Band-Gap
Product Code : JA-SCD-1089
The Resistivity of Semiconductors by Four Probe Method apparatus (SKU JA-SCD-1089) measures the resistivity of a germanium crystal at different temperatures, from which the energy band gap is worked out. A constant current is passed through the outer probes of the four probe arrangement and the voltage across the inner probes is read on an electronic millivoltmeter, so contact resistance does not affect the result. The mounted Ge crystal is heated in an oven up to 200 °C.
Specifications
Parts and ratings from the listing:
| Product | Resistivity of Semiconductors by Four Probe Method at Different Temperatures and Determination of Band-Gap |
| SKU | JA-SCD-1089 |
| Probe arrangement | Four probe |
| Sample | Ge crystal, mounted |
| Oven | Heats up to 200 °C |
| Thermometer | 0-200 °C |
| Constant current supply | Digital; accuracy ±0.25% of reading ±1 digit; load regulation 0.03% (no load to full load) |
| Electronic millivoltmeter | 200 mV range; accuracy ±0.1% of reading ±1 digit; input impedance 1 megohm |
| Displays | 3.5 digit, 7-segment LED, 12.5 mm, auto polarity and decimal indication |
Practical work
- Resistivity of a Ge crystal at room temperature by the four probe method
- Resistivity at raised temperatures up to 200 °C, using the oven
- Energy band gap from the slope of resistivity against temperature
Scope of supply and ordering
The listing covers the probe arrangement, Ge crystal, oven, thermometer, constant current supply and millivoltmeter. Quantities and packing are confirmed on the quotation.
Frequently asked questions
Why use four probes instead of two?
Current flows through the outer probes and voltage is read across the inner ones, so contact resistance does not enter the measurement.
What sample is supplied?
A mounted germanium (Ge) crystal.
How high can the sample be heated?
Up to 200 °C in the oven, read on a 0-200 °C thermometer.
What range does the millivoltmeter have?
200 mV, with accuracy of 0.1% of reading plus 1 digit.
Related products
- Energy Band Gap of PN Junction Diode
- Hall Effect Experiment
- Thermistor Characteristics Apparatus
- Dielectric Constant Apparatus
Solid state physics apparatus is listed in our scientific instrument range.
Request a quote
For the four probe apparatus, send your quantity through our contact page. Tender and project enquiries can be sent through the tenders page.
