They reduced the cost, improved the quality, and figured out how to get it into a phone, i.e. the kind of thing Apple does.
I'm not disputing that Samsung have done a lot of development with the technology. But to suggest the technology was their "innovation" is not correct.
Most of these "lab technologies" come to the giants via small companies, who then sell out, including the patents. Also remember that companies like Samsung have connections to research bodies, and universities and automatically get part ownership of patents originating there too.
Very little these days can be traced back to an individual innovator. While Samsung may not have created it, they may have found an innovative use for the technology. But in phones, that was still Nokia!
Maybe they were the first to use screens curved onto the edges. This would be the innovative feature, but the innovation is the application of the technology, not the AMOLED display.