"The 6.1-inch LCD model will likely sport a metal back [like older iPhone handsets] that will come in several colors", said the source, adding that the two OLED handsets will come in two sizes: one either 6.2 or 6.3 inches long, and the other 5.8 inches.
OLED offers better color contrast and a brighter display compared with LCD.
Last month, Ming-Chi Kuo of KGI Securities indicated that Apple would unveil a new 6.1-inch iPhone next year with the iPhone X design, but a traditional LCD display instead of OLED. Pegatron is now the assembler of the iPhone 8, so both Casetek and Pegatron are hoping that Apple would ask them to integrate the services they offer for iPhone orders in 2018. It's believed that it's harder for Apple to produce additional color options in the glass back design of the iPhone 8 and iPhone X, hence why this year's models are available in fewer color variations than last year's. Meanwhile, the iPhone X only comes in Silver or Space Gray and the iPhone 8 in Silver, Spacer Gray, and Gold. Kuo has claimed that this model will be featuring a 6.1-inch TFT LCD screen.
Foxconn and its smaller Taiwanese rival Wistron split production of the iPhone 8 Plus. Another source claimed that Casetek has already been trying out new casings for the LCD. An industry executive said that Pegatron and Casetek may be able to integrate their offerings for iPhone orders next year by virtue of their close links, much like Foxconn does with its own metal frame and casing production unit.
Other than Foxconn, current suppliers for iPhone metal casings and frames include Catcher Technology and USA -based Jabil. Nikkei has learned that for these two handsets, Apple has chosen to use OLED screens.