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 (UC); 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 (UC) 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 (UC) 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 (UC); 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 (UC) 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 (UC) of the drain electrode . <EOS>