Automated method for measuring the energy gap of p-n junction semiconductor diodes with the temperature-voltage method

Abstract

An automated system for measuring the energy gap E g of a p-n junction semiconductor diodes was presented in this study. The system, based on temperature-voltage (T-V) measurement, was designed and developed as a teaching tool to support teaching for undergraduate students. The energy gap of diodes was measured by varying the diode temperature from 273 to 343 K and by measuring the voltage drop across the diode while the bias current of diodes was kept constant at a specific value. In the proposed system, an Arduino UNO R3 microcontroller was employed to automatically acquire the temperature and voltage drop across the diode. T-V data were plotted, and then the slope and intercept were used to calculate the energy gap by a simplified diode equation. In this system, the temperature and voltage of the two diodes were measured simultaneously at different constant bias currents in the range of 10 μA-10 mA. The average E g value of 1.22 eV obtained in this work is in good agreement with that reported in the literature.