A method of making an OLED device includes providing an anode and a spaced
cathode, and a hole-transporting layer provided between the anode and
cathode, such hole-transporting layer including a first hole-transporting
material having a first glass transition temperature Tg1. The method
further includes providing a first light-emitting layer including as a
main component, a second hole-transporting material having a second glass
transition temperature Tg2, such light-emitting layer disposed between
the hole transporting layer and the cathode and in contact with the
hole-transporting layer, and wherein Tg1 is greater than Tg2.