A display device, comprising: a lower substrate; a first over-coat layer on the lower substrate, the first over-coat layer comprising a first contact hole; a thin film transistor between the lower substrate and the first over-coat layer, the thin film transistor comprising a drain electrode comprising an end portion overlapping the first contact hole, the end portion of the drain electrode comprising an under-cut region; a lower passivation layer between the thin film transistor and the first over-coat layer, the lower passivation layer exposing a side surface of the end portion of the drain electrode; and a light-emitting structure on the first over-coat layer, the light-emitting structure being electrically connected to the thin film transistor through the first contact hole, wherein the drain electrode comprises a first drain electrode and a second drain electrode disposed between the first drain electrode and the lower passivation layer, a side surface of the second drain electrode being closer to a center of the first contact hole than a side surface of the first drain electrode, wherein the lower passivation layer comprises a first portion overlapping the under-cut region of the drain electrode and a second portion outside the end portion of the drain electrode, the second portion being spaced apart from the first portion, wherein the lower passivation layer exposes the side surface of the first drain electrode, and wherein each of the first portion and the second portion of the lower passivation layer includes a region exposed by the first contact hole of the first over-coat layer, wherein the first portion and the second portion of the lower passivation layer are formed by partially cutting off the lower passivation layer by the under-cut region of the drain electrode. a lower substrate; a first over-coat layer on the lower substrate, the first over-coat layer comprising a first contact hole; a thin film transistor between the lower substrate and the first over-coat layer, the thin film transistor comprising a drain electrode comprising an end portion overlapping the first contact hole, the end portion of the drain electrode comprising an under-cut region; a lower passivation layer between the thin film transistor and the first over-coat layer, the lower passivation layer exposing a side surface of the end portion of the drain electrode; and a light-emitting structure on the first over-coat layer, the light-emitting structure being electrically connected to the thin film transistor through the first contact hole, wherein the drain electrode comprises a first drain electrode and a second drain electrode disposed between the first drain electrode and the lower passivation layer, a side surface of the second drain electrode being closer to a center of the first contact hole than a side surface of the first drain electrode, wherein the lower passivation layer comprises a first portion overlapping the under-cut region of the drain electrode and a second portion outside the end portion of the drain electrode, the second portion being spaced apart from the first portion, wherein the lower passivation layer exposes the side surface of the first drain electrode, and wherein each of the first portion and the second portion of the lower passivation layer includes a region exposed by the first contact hole of the first over-coat layer, wherein the first portion and the second portion of the lower passivation layer are formed by partially cutting off the lower passivation layer by the under-cut region of the drain electrode.