All reports point to Apple using an OLED display in just one of its iPhone models this year, while two other models stick to IPS LCD screens. A supply-chain report out of Korea suggests that Apple is aiming to adopt OLED across all models by 2019.
Patently Apple notes a South Korean report that says Apple is to use three Korean suppliers for flexible circuit boards for the iPhone 8, and that one of these has made the OLED claim.
Apple is expected to adopt OLED for about 60 million units […] and double the adoption next year. It aims to use OLED for all its new iPhones by 2019.
Apple’s complex supply-chain means that individual suppliers generally don’t have an accurate sense of the company’s plans, so the report should be treated with caution. That said, starting with one OLED iPhone this year and switching entirely to the display technology two years afterwards doesn’t seem too great a stretch.
It’s been widely reported that Apple will adopt OLED in the iPhone 8, a premium model with edge-to-edge display, while sticking to LCD for an iPhone 7s and 7s Plus.