A couple of days ago we reported that according to tests by DisplayMate, SDC's new 5.1" FHD Super AMOLED panel (used in the GS5) is a lot more efficient than Samsung's previous generation panels (a 27% compared to the GS4 which is actually a little smaller). DisplayMate's Raymond Soneira told us that Samsung said that the improvement mostly came from more efficient OLED materials.
This is quite interesting, and according to my own checks, it seems that indeed Samsung is using new materials. In fact, my sources say that Samsung adoped new and improved phosphorescent materials.