Light-Emitting Diodes: Exploration of Underlying Physics

This paper is the second in the series of LED-dedicated papers that have a goal to systematically investigate the use of LEDs in a general physics course. The first paper, published in the February 2014 issue, provided an overview of the course units where LEDs can be used and suggested three different ways of utilizing LEDs in an introductory physics course: (I) as “black boxes” that allow students to study certain properties of a system of interest, (II) as physical systems that allow students to learn a large amount of physics not usually encountered in a typical introductory course, and (III) as non-traditional devices that allow students to construct concepts that are traditionally a part of a general physics course.¹ The present paper focuses on LED physics and how students can learn this physics through a guided inquiry approach (section II in the classification above). Specifically, we will: (1) introduce the Investigative Science Learning Environment (ISLE) approach,² which we will use as a framework for student learning of the physics of the LEDs; (2) discuss the most important aspects of LED physics that students can learn in a general physics course; and (3) describe in detail classroom activities that follow the ISLE approach which will lead the students to the “discovery” of LED physics described in (2).