Apple is reportedly urging Samsung and LG to develop a new IZO OLED cathode for a four-sided bending iPhone display planned for 2028.
A future iPhone display that bends on all four sides is already forcing a behind-the-scenes scramble in OLED manufacturing, and Apple’s reported plan hinges on a new cathode material that most existing smartphone display lines aren’t built to handle.
The company does not typically ask suppliers to “invent first and worry later.” Instead. it sets requirements. assigns deadlines. and lets supply-chain execution determine whether those ambitions become real.. In this case. the report stated that Apple is pushing Samsung and LG to develop a fundamentally new OLED cathode material called IZO—short for Indium Zinc Oxide—for a four-sided bending display aimed at iPhones in 2028.
A four-sided bending display is not the same as the more familiar curved panels seen on some phones. where only one or two edges curve.. Apple is targeting a panel that curves simultaneously along all four edges.. That design choice is central to the “all-screen” iPhone concept Apple has been reportedly working toward for years. but it also makes the engineering much harder than traditional curved OLED solutions.
One reason is optical distortion.. As the display curves more aggressively, the optical path changes across the panel.. When every edge is bending at once. those distortions can compound. making edge-to-edge image quality inconsistent or visually “off” compared with flatter panels.. For an iPhone that’s meant to look uniform from corner to corner. this is the kind of flaw Apple would be unlikely to tolerate.
To address the distortion problem, Apple’s proposed solution is the move to IZO cathodes.. According to the report. IZO cathodes are more transparent than the cathode materials used in OLED panels found in regular smartphones.. In principle. a more transparent cathode allows more light to pass through. which the report ties directly to cleaner image quality and reduced distortion along the curved edges.
Still, the switch to IZO creates a new bottleneck.. Manufacturing IZO cathodes reportedly requires specialized low-damage TCO sputtering equipment. and current OLED production lines are not set up for it—especially not at the scale needed for a mainstream iPhone launch.. The display materials might solve the optical issue. but the factories still have to be upgraded to produce them reliably and consistently.
LG Display, it was reported, has responded by investing roughly $770 million in infrastructure.. Samsung, meanwhile, is still weighing whether to commit to new, dedicated factory lines for the process.. The difference between “building capacity” and “deciding whether to build” is important here: Apple’s timeline means suppliers cannot treat the project like an optional experiment.
Apple’s approach also appears to be different from what some competitors have tried in recent years.. Curved displays have already appeared in the Galaxy S lineup. and multiple Android manufacturers ship various degrees of curvature even on midrange devices.. But the report suggests Apple is not planning to simply replicate that playbook for its own device. implying it intends to ship the display only when the underlying technology is good enough to meet its own standards.
That matters for the calendar.. The report also raises a timeline tension: Apple has been reported to be working on a four-sided bending display for the 2027 “anniversary iPhone. ” yet the IZO cathode technology is not expected to arrive until the 2028 model.. If that schedule holds. it could mean the 20th anniversary iPhone launches without the improved curved-display approach Apple wants. even if a four-sided bending concept is already in development.
What ultimately connects the dots is Apple’s reputation for only shipping products when it believes the technology has matured.. The report’s framing suggests Apple may choose to hold back on the full IZO-driven improvement rather than risk edge quality that falls short of what an “all-screen” iPhone is supposed to deliver—especially when distortion is already a known challenge in curving display designs across the market.
Apple OLED IZO cathode four-sided bending display LG Display investment Samsung factory lines iPhone 2028 display tech all-screen iPhone