Apple Plans Transparent-Electrode Upgrade for 2028 Four-Edge OLED iPhone: Samsung, LG Display Production Lines
Publish Date: 2026-05-13 17:19:00
Source Domain: www.techtimes.com
Apple disclosed to Korean display partners this week that the four-edge bending OLED display it is developing for a 2028 iPhone will use a transparent indium-zinc-oxide (IZO) cathode layer in place of the current magnesium-silver alloy — a change intended to eliminate image distortion and brightness loss at the screen’s curved corners. Samsung Display and LG Display, Apple’s sole OLED panel suppliers, have already begun preparatory investment to manufacture the technology at scale.
The Trigger: LG Display’s ₩1.106 Trillion Commitment
The timing of the disclosure aligns with a major capital move by LG Display. On April 22, LG Display’s board approved a ₩1.106 trillion ($740 million) investment in new OLED infrastructure, with spending running through June 30, 2028. Industry sources have since identified Apple’s IZO-cathode program as the primary driver of that commitment.
To fabricate the IZO cathode, manufacturers require a low-damage transparent conductive oxide (TCO) sputter — a deposition tool distinct from equipment used on current OLED lines. LG Display is understood to be procuring the machinery first for research and development, then configuring it for mass production.
Why the Cathode Material Matters
Today’s smartphone OLED panels use a cathode composed of a magnesium-silver alloy (Mg:Ag). In a standard flat display this performs adequately, but in a four-edge bending panel — where the screen curves on all four sides to eliminate bezels — the alloy produces visible distortion and reduced luminance at the bends.
In top-emission OLEDs, which dominate the smartphone segment, light exits through the cathode rather than the substrate. Switching to IZO raises electrode transparency, suppressing the distortion that occurs where the panel curves. The change is described by engineers as essential to making a four-edge display commercially viable.
Samsung Display: A New Line Considered Likely
Samsung Display, Apple’s other OLED supplier, has not yet announced…
