Abstract: A light-emitting device includes: a semiconductor stack, including a first semiconductor layer, an active region and a second semiconductor layer; a first contact electrode and a second contact electrode formed on the semiconductor stack, wherein the first contact electrode includes a first contact part formed on the first semiconductor layer and the second contact electrode includes a second contact part formed on the second semiconductor layer; an insulating stack formed on the semiconductor stack, including an opening on the second contact part; a first electrode pad and a second electrode pad formed on the insulating stack, wherein the second electrode pad filled in the opening and connecting the second contact part; wherein the second electrode pad includes an upper surface, and the upper surface includes a platform area and a depression area on the second contact part; wherein the platform area has a maximum height relative to other areas of the upper surface; wherein an area of a projection of the plat

Abstract: A polyurethane derivative and a composition thereof are disclosed. The polyurethane derivative of the present invention has a structure of formula (I). The polyurethane derivative and the composition thereof can be used for increasing light fastness.

Abstract: Provided is a compound of formula (I): wherein A is C2-3 alkylene; m is an integer ranging from 2 to 25; and n is an integer ranging from 3 to 10. An electrolyte for a dye-sensitized solar cell having the compound of formula (I) and/or a compound of formula (II) is further provided for increasing photoelectric conversion efficiency.