🔍 Key Concepts

• LED (Light Emitting Diode) basics: how they produce light at a specific wavelength • Relationship between semiconductor material/bandgap and light color (wavelength) • Difference between electrical operating conditions (voltage/current) and inherent device properties

💭 Think About

• Ask yourself: in an LED, what physical feature actually sets the wavelength (color) of the photons that are emitted? • Would changing the current or voltage through an LED normally turn a red LED into a green LED, or just change something else about the light? • Is the visible color coming from something outside the LED junction (like a lens) or from inside the semiconductor itself?

✅ Before You Answer

• Verify what happens to light color if you increase current through an LED under normal operation. • Consider whether changing applied voltage can make one LED device emit multiple different colors, or mainly affects brightness and forward conduction. • Recall that different LED colors (red, green, blue) are made from different semiconductor materials with different bandgaps.