It's the rumor that simply won't die: Apple will use OLED screens in a future round of iPhones. The latest report comes via Reuters citing unnamed sources from South Korea's Electronic Times (Korean). Also cited was last month's report from Nikkei that stated Apple's intent for the gorgeous screen tech is to add it to the 2018 iPhone.
Apparently the two companies making OLED displays, LG and Samsung, are close to a deal with Cupertino and they're planning to spend over $12 billion to increase production capacity. Hmm, that lines up with previous info from LG about new manufacturing lines. Reuters notes that Apple "will likely" offer some cash to offset LG and Samsung's investment, too. Keep in mind that Apple's already using OLED, it's just in a much smaller form: the Apple Watch.