Band gap of germanium

Principle

The conductivity of a germanium test sample is measured as a function of temperature. The energy gap is determined from the measured values.

Benefits

• Hall effect unit to control all parameters (temperature, voltage) and supports intrinsic , p- and n-type Ge crystals
• Can also be used to study Hall effect in p and n-type Ge

Tasks

1. The current and voltage are to be measured across a germanium test-sample as a function of temperature.
2. From the measurements, the conductivity s is to be calculated and plotted against the reciprocal of the temperature T. A linear plot is obtained, from whose slope the energy gap of germanium can be determined.

Learning objectives

• Semiconductor
• Band theory
• Forbidden band
• Intrinsic conduction
• Extrinsic conduction
• Impurity depletion
• Valence band
• Conduction band