Electrical and optical measurements of the bandgap energy of a light-emitting diode

Matthieu Petit (1, 2) , Lisa Michez (2, 1) , Jean-Manuel Raimundo (2, 1) , Philippe Dumas (2, 1)

1 AMU POLYTECH - Polytech Marseille
2 CINaM - Centre Interdisciplinaire de Nanoscience de Marseille

Semiconductors materials are at the basis of electronics. Most electronic devices are made of semiconductors. The operation of these components is well described by quantum physics which is a little mysterious to students. One of the intrinsic parameters of semiconductors is their bandgap energy Eg. In the case of light-emitting diodes (LEDs) Eg fixes the colour of the light emitted by the diodes. We propose in this article a lab work allowing a comparison of Eg of a green LED obtained by both electrical and optical measurements. The two slightly different results can be explained by the theoritical knowledges of the students on solid physics and electronic devices internal architecture.

Mots clés: bandgap; semiconductors; p-n junctions; LED; light-emitting diode

Domaines: Science des matériaux [cond-mat.mtrl-sci]

Matthieu Petit, Lisa Michez, Jean-Manuel Raimundo, Philippe Dumas. Electrical and optical measurements of the bandgap energy of a light-emitting diode. Physics Education, 2016, 51 (2), pp.025003. ⟨10.1088/0031-9120/51/2/025003⟩. ⟨hal-01266699⟩