Abstract
<title>Abstract</title> <p>Accurate determination of the semiconductor energy band gap is essential for understanding the electrical properties of semiconductor materials and represents a fundamental experiment in undergraduate solid-state physics laboratories. However, conventional laboratory methods are often constrained by unstable temperature conditions, limited measurement sensitivity, and fragmented experimental procedures, reducing both measurement accuracy and students’ understanding of the relationship between semiconductor theory and experimental observations. This study presents the development of an automated laboratory platform for semiconductor energy band gap measurement based on current–voltage characterization with Fuzzy-PID temperature stabilization. The proposed system integrates automated temperature control, current–voltage data acquisition, real-time visualization, and digital data storage into a single experimental platform. Temperature stabilization was achieved using a Fuzzy-PID controller to minimize thermal fluctuations during measurement, thereby improving the reliability and repeatability of energy band gap determination. The system was experimentally validated using Silicon and Germanium diodes over a controlled temperature range. Compared with a conventional PID controller, the proposed Fuzzy-PID controller reduced the steady-state error from 1.67% to 0.65% at a 50°C setpoint and from 1.56% to 0.89% at an 80°C setpoint, resulting in improved thermal stability throughout the experiment. Using the forward-bias method, the measured energy band gap of Silicon ranged from (1.0601 ± 0.0072) eV to (1.0833 ± 0.0075) eV, in close agreement with the theoretical value of 1.1 eV. For Germanium, measured values of (0.7706 ± 0.1352) eV and (0.6170 ± 0.0755) eV were obtained under forward currents of 18 mA and 25 mA, respectively, closely matching the theoretical value of 0.67 eV. Overall, the developed system provides a reliable, cost-effective, and educationally effective platform for semiconductor energy band gap experiments while supporting undergraduate laboratory instruction and semiconductor characterization research.</p>