Five decades of determining Planck’s constant using light emitting diodes in Undergraduate Laboratories - A Review


  • Harish V Government First Grade College, Bapujinagara, Shivamogga.
  • Shivaprasad N G Government First Grade College, Srirangapatna-571438, Karnataka
  • Ashok G V Government College, Mandya-571401, Karnataka
  • Nagendra Naik K Government First Grade College, Bapujinagara, Shivamogga.


Planck’s constant, Light emitting diode, Cut-off voltage, Turn-on voltage, Barrier potential, Activation voltage


Determination Planck’s constant using LED’s has been a favourite experiment even from student perspective because of its simplicity and taught in undergraduate laboratories for the past five decades. Several modifications and improvements adopted in both experiment procedure as well as data analysis part of this experiment during this period have been revisited in paper. From the simplest experiment to determine turn-on voltages using human judgement with naked eye to advanced equipment to detect even pico ampere current flowing through LED’s have been proposed by various researchers. Many of these proposals were successful in arriving at Planck’s constant with excellent agreement with standard value. Reasons for yielding unrealistic values of Planck’s constant have also been reported by several researchers.

Author Biographies

Harish V, Government First Grade College, Bapujinagara, Shivamogga.

Government First Grade College, Bapujinagara, Shivamogga, Karnataka, India.

Shivaprasad N G, Government First Grade College, Srirangapatna-571438, Karnataka

Associate Professor of Physics

Department of Physics

Government First Grade College, Srirangapatna - 571 438, Karnataka, India.

Ashok G V, Government College, Mandya-571401, Karnataka

Associate Professor of Physics

Department of Physics

Government College, Mandya - 571 401, Karnataka, India.

Nagendra Naik K, Government First Grade College, Bapujinagara, Shivamogga.

Assistant Professor of Environmental Science

Department of Environmental Science

Government First Grade College, Bapujinagara, Shivamogga - 577 201, Karnataka, India.


Crandall and Delord, Minimal apparatus for determination of Planck’s constant, American Journal of Physics, 51, 90, 1983. DOI: 10.1119/1.13405

R D MacQueen, Photocell experiment for secondary school physics, MA Thesis, University of British Columbia, 1966. DOI: 10.14288/1.0104619

HH Hall and RP Tuttle, Photoelectric effect and Planck’s constant in the introductory laboratory, American Journal of Physics, 39, 50, 1971. DOI: 10.1119/1.1986055

R A Powell, Photoelectric effect: Back to basics, American Journal of Physics, 46(10), 1046, 1978, DOI: 10.1119/1.11493.

PJ O'conner and LR O'conner, Measuring plank's constant using a light emitting diode, The Physics Teacher 12(7), 423-425, 1974. DOI: 10.1119/1.2350479

Dennis Sievers and Alan Wilson, Determining Planck's Constant Using a Light-emitting Diode, The Science Teacher , 56 (2), 44, 1989.

L Nieves etal., Measuring the Planck constant with LED’s, The Physics Teacher 35, 108 1997, DOI: 10.1119/1.2344608.

Feng Zhou and Todd Cloninger, Computer-Based Experiment for Determining Planck's Constant Using LEDs, The Physics Teacher 46, 413, 2008, DOI: 10.1119/1.2981288.

Ryan Eagan, Experimental Determination of Planck's Constant, 2011,

Valaria Indelicato etal., Analysis of LED data for the measurement of Planck’s constant in the undergraduate laboratory, Eur. J. Phys. 34, 819–830, 2013, DOI:10.1088/0143-0807/34/4/819.

Richard Ward, Using infrared and ultraviolet LEDs to improve the determination of the Planck constant, Physics Education, 20, 2013, DOI: 10.1088/0031-9120/48/1/F06

Andrea Checchetti and Alessandro Fantini, Experimental Determination of Planck’s constant using Light Emitting Diodes (LEDs) and Photoelectric Effect, World Journal of Chemical Education, 3(4), 87-92, 2015, DOI:10.12691/wjce-3-4-2

Cliff Orori Mosiori etal., Determination of Planck’s Constant using Light Emitting Diodes, Traektoriâ Nauki = Path of Science, 3(10), 2017. DOI:10.22178/pos.27-2

Francesca Santonocito etal., From led light signboards to the Planck’s constant, IOP Conf. Series: Journal of Physics: Conf. Series 1076, 012009, 2018, DOI:10.1088/1742-6596/1076/1/012009

C Calvo Mole etal., Determination Of The Planck Constant Through The Use Of LEDs, Revista Cubana De F´isica,. 36(2), 125, 2019.

Mila Bileska, Measuring Planck’s Constant Using Light Emitting Diodes, Journal of Physics & Astronomy, 8(3), 2020, DOI: 10.37532/2320-6756.2020.8(3).198

F Herrmann and D Schatzle, Question #53. Measuring Planck’s constant by means of an LED, American Journal of Physics, 64, 1448, 1996, DOI: 10.1119/1.18404

Roger Morehouse, Answer to Question #53. Measuring Planck’s constant by means of an LED, American Journal of Physics 66, 12, 1998, DOI: 10.1119/1.19034

Chetan Kotabage, Is a glowing LED meaningful to determine the Plank's constant accurately? Proc. SPIE 11143, Fifteenth Conference on Education and Training in Optics and Photonics: ETOP 2019, 111432S, 2 July 2019, DOI: 10.1117/12.2508193

Dean Zollman and Ian G Bearden, Determining Planck’s constant with LEDs—what could possibly go wrong? Phys. Educ. 55, 015011, 2020, DOI: 10.1088/1361-6552/ab525d