All three iPhones in 2020 will receive OLED displays. This does not mean, however, that all of them will be equal. Two of them will receive more advanced technology, which will result in a thinner display.
Successors of the iPhone 11 Pro and Pro Max will probably receive screens from Samsung. A Korean company is able to separate the touch layer, thanks to which the screens are thinner. These displays are to be used in the top two models - 5,4 ″ and 6,7 ″.
These panels are OLED with a built-in touch layer, exactly on the top of the display. Until now, the touch layer was stuck to the screen. By eliminating this element, you can produce a thinner screen. Samsung Display has successfully commercialized the OLED panel with a touch layer directly in the display, which is called 'Y-OCTA'.
The lower model with 6,1 ″ screen will probably be equipped with panels from Samsung and LG. The latter company also has the ability to produce panels with a tactile layer, but is not able to provide them with the right amount. It can be expected that this iPhone model will be a continuation of the 11 model. Therefore, its OLED panel will be cheaper to produce, and hence the touch layer will be separated.
Apple will probably give up the Chinese supplier BOE in 2020. I wonder if, in connection with functional novelties, smartphones will become more expensive again. In my opinion, current prices are already at its peak, more simply not worth paying for a smartphone.