Photosensing transistors, display panels employing a photosensing transistor, and methods of manufacturing the same, include a gate layer, a gate insulation layer on the gate layer, a channel layer on the gate insulation layer, an etch stop layer on a partial area of the channel layer, a source and a drain on the channel layer and separated from each other with the etch stop layer being interposed between the source and the drain, and a passivation layer covering the source, the drain, and the etch stop layer, wherein the source is separated from the etch stop layer.