Apple doesn’t ask its suppliers to build things. It tells them to, hands them a deadline, and watches billions of dollars move on product lines and supply chains.
The company is reportedly pushing Samsung and LG to build a fundamentally new OLED cathode material called IZO (Indium Zinc Oxide) for a four-sided bending display planned for 2028 iPhones (via ETnews).
What is a four-sided bending display?
LG Display has reportedly responded by investing approximately $770 million in infrastructure. Samsung is still deciding whether to go ahead with committing to new, dedicated factory lines.
However, Apple isn’t waiting for either of them to make up their minds; it needs the display done. Unlike the flat OLED panels that the company has used on iPhones since 2020, the company wants a four-sided bending display that curves on all four edges simultaneously.
Apple wants the display for the “all-screen” iPhone that it has been reportedly building for years. However, the problem is optical distortion at the curved edges, which compounds even more when all four sides are bending at once.
How is Apple planning to fix the curved display’s biggest problem?
The fix that Apple proposes is IZO cathodes, which, unlike the cathodes in OLED panels on regular smartphones, are more transparent and therefore allow more light to pass through. A more transparent cathode means less distortion at the curved edges, cleaner image quality, and a display that doesn’t look distorted at the edges.
The catch, however, is that manufacturing IZO cathodes requires specialized low-damage TCO sputtering equipment that current OLED lines aren’t equipped to handle, especially at scale. I know what you’re thinking. Samsung already featured curved displays on the Galaxy S series. Several Android manufacturers also provide slightly curved displays, even on midrange phones.
However, what Apple isn’t doing is simply copying that playbook. The IZO cathode push signals that the company isn’t shipping a curved display until it perfects the technology, which, by the way, is a well-known problem on the mid-range Android smartphones I was talking about.
What puzzles me, however, is that the company is working on a four-sided bending display for the 2027 anniversary iPhone, but the IZO cathode technology won’t arrive until the 2028 model.
Does this mean that the 20th anniversary iPhone will ship without the improved curved display? Sounds like it, but we shouldn’t forget that Apple never ships a product unless it thinks it has perfected it.
