I want to know the answer to the following question:
What type of diode was used to help discover near-infrared light emission?
All the background I'm provided with is that "On August 8, 1962, Biard and Pittman filed a patent titled "Semiconductor Radiant Diode" based on their findings, which described a zinc diffused p–n junction LED with a spaced cathode contact to allow for efficient emission of infrared light under forward bias.". Is that enough to answer the question?