The original Doctor Solar was a physicist named Dr. Raymond Solar. He was exposed to a massive amount of radiation in an attempt to rescue a fellow worker (Dr. Bentley). Bentley was trying to recover from the sabotaging of a nuclear power facility by a Dr. Rasp. He amazingly survived and soon discovered that he had powers to convert his human form into any kind of energy (E = mc²). Use of these powers depleted his store of energy which would require him to re-expose himself to radiation sources for replenishment. Using his new powers, he began searching for the "mastermind" behind the plot responsible for the sabotage of the nuclear lab that caused his condition in the first place. This evil mastermind (named Nuro) was a continuing character Doctor Solar clashed with many times. Nuro often used a robot 'double' of himself called Orun in his schemes.
Doctor Solar could manipulate matter at the atomic level. He could fly and fire bolts of energy. When Doctor Solar was using his powers his skin would turn green.
After he being disintergrated by a nuclear accident physicist Doctor Philip Solar managed to drag his form back together by willpower alone, gaining superhuman powers as a result. He began fighting crime, and shortly afterwards added a costume and a superhuman title.
Doctor Solar actually didn't get a superhero costume until the fifth issue of his comic. Also, 'Doctor Solar' was his 'real' or 'civilian' name. When he went into action, he was known as The Man of the Atom. His costume was intended to shield others from his radiation. Also, when he went into action and 'powered up', his skin turned green.
His original run lasted 27 issues, from October 1962 to April, 1969. In the early 1980s, the series was resumed with issue #28 and lasted 4 issues.