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.