Long before silicon chips, smartphones and high-speed communication transformed everyday life, Indian scientist Jagadish Chandra Bose was investigating the unusual behaviour of crystals and electromagnetic waves.
More than a century later, those experiments are finding renewed relevance in semiconductors, microwave technology and quantum science.
Bose’s experiments with galena, or lead sulphide, crystals and metal point contacts revealed electrical behaviour fundamental to semiconductor devices.
Remarkably, he was investigating these effects before quantum mechanics and modern semiconductor theory had been developed.
“JC Bose was a very astute experimentalist and could predict that semiconducting behaviour could occur naturally in materials such as galena, without the kind of deliberate doping used in modern semiconductor technology,” he added.
Long before silicon chips, smartphones and high-speed communication transformed everyday life, Indian scientist Jagadish Chandra Bose was investigating the unusual behaviour of crystals and electromagnetic waves. More than a century later, those experiments are finding renewed relevance in semiconductors, microwave technology and quantum science.
Bose’s experiments with galena, or lead sulphide, crystals and metal point contacts revealed electrical behaviour fundamental to semiconductor devices. Remarkably, he was investigating these effects before quantum mechanics and modern semiconductor theory had been developed.
“From the perspective of modern solid-state physics, the significance of Bose’s experiments becomes clearer,” said Dr MS Ramkarthik, theoretical physicist and assistant professor in the Department of Physics at VNIT Nagpur. “JC Bose was a very astute experimentalist and could predict that semiconducting behaviour could occur naturally in materials such as galena, without the kind of deliberate doping used in modern semiconductor technology,” he added.
One of the most intriguing aspects of Bose’s research was his use of crystals as detectors of electromagnetic waves. His point-contact arrangement brought a metal into contact with a crystal, producing a device capable of detecting electrical disturbances. The experiments also showed rectification — the preferential flow of current in one direction — a basic principle behind semiconductor diodes used extensively in modern electronic circuits.
Bose subsequently patented his detector. His US patent, filed in 1901 and granted in 1904, described a point-contact device using a crystal rectifier to detect electrical disturbances.
