Light-emitting device and input/output device

An input/output device comprising:

• a first substrate;
• a first transistor over the first substrate;
• a light-emitting element over the first transistor;
• a first conductive layer over the light-emitting element;
• a first insulating layer over the first conductive layer;
• a second conductive layer over the first insulating layer;
• a second substrate over the second conductive layer;
• and
• a second transistor and a capacitor between the first conductive layer and the second substrate,
• wherein the first transistor and the light-emitting element are electrically connected to each other,
• wherein the second transistor and the capacitor are electrically connected to each other,
• wherein the first conductive layer overlaps with the light-emitting element,
• wherein the first conductive layer is configured to transmit light emitted by the light-emitting element,
• wherein the first conductive layer is electrically connected to the second conductive layer,
• wherein the second conductive layer is formed on a same plane as a gate electrode or source and drain electrodes of the second transistor, and
• wherein the second conductive layer comprises a same material as a material of the gate electrode or the source and drain electrodes of the second transistor.