This document discusses active-matrix organic light-emitting diode (AMOLED) displays. AMOLED is a type of OLED display technology that is becoming more common in mobile devices. It consists of only 3 layers - a backplane with thin film transistors, an organic light emitting diode layer, and a cathode. The thin film transistors control the current to each pixel to light it up. AMOLED displays are thinner, more flexible, and use less power than LCD displays, but have shorter lifetimes and lower efficiency of blue OLED materials.