A light source comprising: a substrate; a light emitting structure comprising: a first layer of semiconductor material of a first conductivity type provided on said substrate; an active layer overlying said first layer; and a second layer of semiconductor material of an opposite conductivity type from said first conductivity type overlying said active layer; a barrier that divides said light emitting structure into first and second segments that are electrically isolated from one another, said barrier comprising a trench extending through said light emitting structure, said trench including a first portion formed above a level of an upper surface of the first layer and a second portion formed below the level of the upper surface of the first layer and extending to the substrate; an insulating layer that is formed on a bottom surface of said second portion of said trench and a side surface of said second segment; a serial connection electrode that electrically connects said first layer in said first segment to said second layer in said second segment, wherein said serial connection electrode comprises a layer of electrically conducting material deposited in said trench, said insulating layer preventing said layer of electrically conducting material from making direct contact with said first layer er and said active layer in said second segment; a first power contact electrically connected to said second layer in said first segment; and a second power contact electrically connected to said first layer in said second segment, wherein said first and second segments generate light when a potential difference is created between said first and second power contacts, said insulating layer extends to a top surface of said second layer of said second segment so that the insulating layer is provided between said active layer in said second segment and said serial connection electrode positioned above said active layer in the second segment, and the light source further comprises an Indium Tin Oxide layer formed on said second layer of said second segment and within an area of said second layer of said second segment in a top view, characterised in that, said ITO layer extends onto said insulating layer on said top surface of said second layer of said second segment and contacts said serial connection electrode on said insulating layer. a substrate; a light emitting structure comprising: a first layer of semiconductor material of a first conductivity type provided on said substrate; an active layer overlying said first layer; and a second layer of semiconductor material of an opposite conductivity type from said first conductivity type overlying said active layer; a first layer of semiconductor material of a first conductivity type provided on said substrate; an active layer overlying said first layer; and a second layer of semiconductor material of an opposite conductivity type from said first conductivity type overlying said active layer; a barrier that divides said light emitting structure into first and second segments that are electrically isolated from one another, said barrier comprising a trench extending through said light emitting structure, said trench including a first portion formed above a level of an upper surface of the first layer and a second portion formed below the level of the upper surface of the first layer and extending to the substrate; an insulating layer that is formed on a bottom surface of said second portion of said trench and a side surface of said second segment; a serial connection electrode that electrically connects said first layer in said first segment to said second layer in said second segment, wherein said serial connection electrode comprises a layer of electrically conducting material deposited in said trench, said insulating layer preventing said layer of electrically conducting material from making direct contact with said first layer er and said active layer in said second segment; a first power contact electrically connected to said second layer in said first segment; and a second power contact electrically connected to said first layer in said second segment, wherein said first and second segments generate light when a potential difference is created between said first and second power contacts, said insulating layer extends to a top surface of said second layer of said second segment so that the insulating layer is provided between said active layer in said second segment and said serial connection electrode positioned above said active layer in the second segment, and the light source further comprises an Indium Tin Oxide layer formed on said second layer of said second segment and within an area of said second layer of said second segment in a top view, characterised in that, said ITO layer extends onto said insulating layer on said top surface of said second layer of said second segment and contacts said serial connection electrode on said insulating layer.