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For Educators · LED Band Gap

LED Band Gap for a laser beam

Built for educators teaching it to a class. Drop a live demo into a lecture or assign it as a shareable link — no lab installs. Simulate a laser beam live below — adjust the inputs and watch it respond, right in your browser.

LED Band Gap & ColorLive

from energy gap to photon

590 nm

2.10 eV band gap

Controls

Presets

Band gap Eg (eV)

An LED emits light when electrons drop across the semiconductor's band gap, each releasing a photon of energy equal to that gap. Since photon energy fixes wavelength (λ = 1240/Eg in nm), the band gap directly sets the color — which is why blue LEDs needed a whole new material (gallium nitride) and a Nobel Prize to achieve.

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Data Inspector

Wavelength590 nm

Regionvisible

MaterialGaP/AlInGaP (green-red)

Governing equation

λ = \frac{h c}{E _{g}} = \frac{1240}{2.10 eV} = 590 nm

Reading this result: λ = 1240/Eg puts this 2.10 eV gap at 590 nm — a wider gap means a bluer photon, which is exactly why blue LEDs needed the high-gap GaN family.

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Frequently asked questions

Is this good for educators?: Yes — this version of "LED Band Gap for a laser beam" is framed for educators teaching it to a class. Drop a live demo into a lecture or assign it as a shareable link — no lab installs.
Do I need to install anything?: No. It runs in any modern browser, free, with no account required.