2026/02/04 by P Kamiński · 1 voice
Physics and Astronomy · Social Sciences · #Experimental and Theoretical Physics Studies #Quantum and Classical Electrodynamics #Science Education and Pedagogy
paper · doi:10.1088/1361-6552/ae37bd
openalex publication_date 2026/02/04 · openalex created_date 2026/02/06 · openalex updated_date 2026/05/21
Abstract Quantum mechanics has revolutionised our understanding of reality. At the heart of this theory lies Planck’s constant <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:mi>h</mml:mi> </mml:mrow> </mml:math> , which plays a fundamental role in describing the behaviour of matter on the smallest scales. In this paper we present a teaching approach that combines a concise historical overview of the origin of h with a simple experiment in which students determine its value from measurements on a photovoltaic panel. The article integrates methodologies from Science, Technology, Engineering, and Mathematics and problem-based learning to demonstrate how contemporary educational techniques can not only aid in understanding quantum concepts, but also enable the experimental determination of one of the most fundamental constants of nature. Using low-cost components available in school and introductory university laboratories, students measure the threshold voltage of a photovoltaic cell for different wavelengths of light and, by analysing the linear dependence of the electron energy <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:mi>e</mml:mi> <mml:mi>U</mml:mi> </mml:mrow> </mml:math> on <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:mi>c</mml:mi> <mml:mrow> <mml:mo>/</mml:mo> </mml:mrow> <mml:mi>λ</mml:mi> </mml:mrow> </mml:math> to obtain an experimental estimate of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:mi>h</mml:mi> </mml:mrow> </mml:math> . In contrast to other works where light-emitting diodes have been used to determine Planck’s constant (Chakarvarti and Sharma 1988 Phys. Educ. 23 416; Ward 2013 Phys. Educ. 48 20–1; Morton and Abraham 1986 Phys. Educ. 21 414; Korpal et al 2023 Phys. Educ. 58 045003), this article presents a method of experimentally determining <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:mi>h</mml:mi> </mml:mrow> </mml:math> , by measuring the threshold voltage of a photovoltaic panel as a function of the frequency of incident light. The proposed experiment can be easily conducted in a school setting, for example as a group project under the guidance of a teacher. It illustrates that core quantum concepts can be explored experimentally even at the introductory level. Furthermore, this experiment can complement university-level lectures or laboratory courses.