Determination of the Band-Gap of a Semiconductor: Germanium Chip Using Four Probe Set-Up

This paper states the step by step experimental approach in determining the band gap of a semiconductor (Germanium crystal) using four probe set-up, which is a method that permits measurements of resistivity in samples (Germanium). Starting with an introduction, this paper farther highlights about the Germanium crystal and continues to give a brief overview of the electronic conduction in solids. Experiment was conducted to determine the band gap of a germanium crystal. The apparatus used are mentioned, and the procedures taking in determining the required results are explicitly stated. Observations were made, and the readings observed are tabulated. Thus, it is observed that a plot of the log of resistivity in ohms-meter against the inverse of temperature in (kelvin) -1 gives a curve whose slope was used to determine the band gap of the semiconductor material, (the germanium crystal). The calculation is shown in this paper, and the bandgap calculated is approximately 0.70 eV, which tallies with the standard experimental result.