You asked too broad a question. Samsung and Mot among others use such but not in all models. You also have the issue of battery time. To counter the nuclear powered light source you often hear folk rail against the few hours of use.
Bob
Which manufacturers use OLED screens on their phones? Most phones use LED screens which are totally useless outdoors. I realize they are more costly to produce. I'm surprised that the iPhones or Galaxy phones don't use these.

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