The Galaxy S4 produced by Samsung Electronics saw much-improved device performance from its predecessors. Among emitting layer (EML) materials, green host materials were changed from fluorescence to phosphorescence, while the blue prime layer was first introduced to enhance the lifespan and efficiency of the blue host. In the case of the Galaxy S5, the sequel to the Galaxy S4, a new layer called additional electron transfer layer (aETL) was added to further extend the efficiency and lifespan of EML color materials.

Samsung Display has produced AMOLED panels equipped with devices employing blue prime and aETL materials. The Galaxy S6 and Galaxy S6 Edge recently released by Samsung Electronics used AMOLED panels applying a new device called the M7 that has blue prime and aETL materials. Its structure is the same with that of the former device. The M7 remains largely unchanged, except for changes in suppliers for organic materials and the thickness of the organic layer to improve performance.

Compared to Samsung Display, LG Display is a second mover in the market. The company launched its FMM RGB type panels and invested in production facilities later than the counterpart. Consequently, its device development began later than Samsung Display.

For instance, the panel maker still relies on fluorescent materials to produce the green host of the EML. However, recently, the company has made tremendous research and development efforts to enhance device performance. Devices using new functional layers, such as electron blocking layer (EBL) or hole blocking layer (HBL), are currently under development. AMOLED panel devices developed by Samsung Display and LG Display are moving towards a longer lifespan and higher resolution through a series of improvements.

In the case of AMOLED TV, Samsung Display had used the fine metal mask (FMM) RGB technique. But it has discontinued its AMOLED TV business since the release of an AMOLED TV panel in 2013. On the contrary, LG Display’s WOLED type panels that were built on the open mask technique have seen rapid developments since its launch in 2013, including an extended product lineup and expanded production line. Based on a two-color two-stack vertical tandem structure, the early WOLED TV device produced white light using a combination of YG and blue.

The resulting white showed a reduction in color purity when compared to white light generated by mixing the three primary colors, red, green, and blue. Also, the color had low brightness due to the vertical structure. To improve the brightness and color purity of white light, LG Display developed a two-color three-stack WOLED device structure and applied it to the curved ultra-high definition (UHD) WOLED TV released in late 2014.