Patent ID: 8723196

Claim:
A light-emitting device having at least first and second light-emitting elements exhibiting different emission colors, each of the first and second light-emitting elements comprising: a first electrode having a non-light-transmitting property; a first layer containing a first substance and a second substance over the first electrode; a second layer including a light-emitting layer over the first layer; a third layer containing a third substance and a fourth substance over the second layer; and a second electrode having a light transmitting property over the third layer, wherein the first substance has hole transporting property, wherein the second substance has electron accepting property with respect to the first substance, wherein the third substance has electron transporting property, wherein the fourth substance has electron donating property with respect to the third substance, wherein a distance between the first electrode and the second electrode in the first light-emitting element is different from that in the second light-emitting element.