Here’s why BLUE LEDs took nearly 30 years to create. 🔵💡🤯 Red and green LEDs were already practical by the 1960s. So why did it take researchers decades to produce an efficient blue LED? The problem came down to materials science. An LED works by passing electrical current through a semiconductor. When electrons and holes recombine inside the material, energy is released as photons — and the material determines the color of that light. Producing blue light requires photons with much higher energy than red or green light. That meant researchers needed a semiconductor with a much larger band gap. One of the most promising materials was gallium nitride (GaN). But GaN was incredibly difficult to work with. Growing high-quality GaN crystals was extremely challenging, and researchers struggled to produce the material with the right electrical properties. Even when they could make the semiconductor, creating efficient layers — especially the crucial p-type layer needed for a practic...