Light-emitting device, display device, photoelectric conversion device, electronic equipment, and method for manufacturing light-emitting device

This light-emitting device includes a first substrate provided with a first principal surface and a second principal surface on which a light-emitting element is disposed, and a second substrate joined to the first principal surface. A transistor for controlling the light-emitting element is disposed on the first substrate. The transistor includes a gate electrode extending in a direction crossing the first principal surface, a first diffusion region functioning as one of a source region and a drain region that is disposed on the first principal surface, and a second diffusion region functioning as the other of the source region and the drain region that is disposed on the second principal surface. The first diffusion region and the second diffusion region are disposed side by side in the direction crossing the first principal surface.