In the "Fact of the Matter" segment of the Daily Planet programme on the Discovery Channel 2002-11-14, there was a slip of the tongue. In response to the question "What is a Light Emitting Diode?", the answer was "It's a piece of silicon...". Although silicon with an indirect bandgap has recently been shown to emit light, most if not all LEDs are made of III-V compound semiconductors (e.g., GaAs, GaN, GaP, InAs, etc.) with a direct bandgap.
