A device comprising: a semiconductor light emitting device; and a mount comprising: a body having a first surface and a second surface opposite to the first surface, wherein the semiconductor light emitting device is attached to the first surface of the body; electrical connections within the lateral extent of the semiconductor light emitting device extending through the body from the semiconductor light emitting device to the second surface; a quantity of a first material attached to the first surface of the body, the quantity of first material forming a wall around the semiconductor light emitting device; electrical contacts formed on the second surface of the body, each of the electrical contacts extending along the second surface of the body from one of the electrical connections to a position located within a lateral extent of the wall; the device further comprising a quantity of a second material disposed between the semiconductor light emitting device and the wall; characterized in that the second material has a higher index of refraction than the first material, such that light emitted from the semiconductor light emitting device is reflected at the interface of second material and wall by total internal reflection. a semiconductor light emitting device; and a mount comprising: a body having a first surface and a second surface opposite to the first surface, wherein the semiconductor light emitting device is attached to the first surface of the body; electrical connections within the lateral extent of the semiconductor light emitting device extending through the body from the semiconductor light emitting device to the second surface; a quantity of a first material attached to the first surface of the body, the quantity of first material forming a wall around the semiconductor light emitting device; electrical contacts formed on the second surface of the body, each of the electrical contacts extending along the second surface of the body from one of the electrical connections to a position located within a lateral extent of the wall; the device further comprising a quantity of a second material disposed between the semiconductor light emitting device and the wall; characterized in that the second material has a higher index of refraction than the first material, such that light emitted from the semiconductor light emitting device is reflected at the interface of second material and wall by total internal reflection. a body having a first surface and a second surface opposite to the first surface, wherein the semiconductor light emitting device is attached to the first surface of the body; electrical connections within the lateral extent of the semiconductor light emitting device extending through the body from the semiconductor light emitting device to the second surface; a quantity of a first material attached to the first surface of the body, the quantity of first material forming a wall around the semiconductor light emitting device; electrical contacts formed on the second surface of the body, each of the electrical contacts extending along the second surface of the body from one of the electrical connections to a position located within a lateral extent of the wall; the device further comprising a quantity of a second material disposed between the semiconductor light emitting device and the wall; characterized in that the second material has a higher index of refraction than the first material, such that light emitted from the semiconductor light emitting device is reflected at the interface of second material and wall by total internal reflection.