Estimating the Planck´s Constant, an undergraduate experiment with STEM approach

Abstract

One of the permanent concerns in teaching at the university level is that the student is able to understand the concepts taught in the different courses and create correlations between them that allow the construction of solid and interdisciplinary knowledge. The STEM (Science, Technology, Engineering, and Mathematics) methodology allows students to connect ideas, develop experimental procedures and implement computational simulations to solve specific problems in the different fields of science and engineering. In this work, the STEM methodology is used to experimentally estimate the value of Planck's constant, based on problem-based learning that involves not only the theoretical study of semiconductor physics using the principle of operation of a light-emitting diode (LED) but also allows the development of computational and scientific programming skills by using the Arduino platform as a tool for data acquisition and analysis. In the proposal presented here, an Arduino Uno is used to control the current flowing through an LED, thus allowing to build a characteristic curve of current (I) vs. voltage (V) and thus determine the value of the bandgap of the semiconductor that makes up the P-N junction of the LED. If LEDs with emission at different wavelengths are used, it is possible to determine by means of a linear fit the value of the Planck’s constant. The results obtained are promising, as long as this is understood as a low-cost system that allows having errors of around 4% with respect to the values obtained in the literature.