Greenleaf Whittier Pickard

Greenleaf Whittier Pickard (* February 14, 1877; † January 8, 1956 ) was an American engineer and pioneer in early radio and radio art. He realized that buildings and other objects can reflect radio waves.

He also discovered in research with crystals as receivers that elements with crystal structure as silicon have the best semiconductor properties.

On 30 August 1906, he registered the first patent for a silicon diode. The operation of semiconductor devices, however, was detected only much later.