A light emitting device comprising: - a light emitting diode, formed by semiconductor materials (100, 102, 104) on a substrate, that emits light when a forward bias voltage is applied to terminals of the light emitting diode, and - an electrostatic discharge protection diode, formed by semiconductor materials (100, 102, 104) on the substrate, such that the electrostatic discharge protection diode and the light emitting diode are formed on the same chip, wherein the electrostatic discharge protection diode is connected in an anti-parallel configuration to the light emitting diode, such that the anode of the light emitting diode is connected to the cathode of the electrostatic discharge protection diode and the cathode of the light emitting diode is connected to the anode of the electrostatic discharge protection diode, for protecting the light emitting diode from damage by shunting current away from the light emitting diode when a reverse bias voltage above a threshold level is applied to the terminals of the light emitting diode, wherein the electrostatic discharge protection diode comprises a junction of N-type material and P-type material forming a PN junction, and wherein a metal layer portion (68, 80, 88, 92, 93) contacts the N-type material of the electrostatic discharge protection diode, characterised in that - an area of the substrate taken up by the electrostatic discharge protection diode is less than 30% of the total area taken up by the light emitting diode and the electrostatic discharge protection diode on the substrate, - a length of the PN junction of the electrostatic discharge protection diode is at least twice a width of the PN junction of the electrostatic discharge protection diode, and - a length of the metal layer portion (68, 80, 88, 92, 93) contacting the N-type material of the electrostatic discharge protection diode is at least 50% of the length of the PN junction of the electrostatic discharge protection diode. - a light emitting diode, formed by semiconductor materials (100, 102, 104) on a substrate, that emits light when a forward bias voltage is applied to terminals of the light emitting diode, and - an electrostatic discharge protection diode, formed by semiconductor materials (100, 102, 104) on the substrate, such that the electrostatic discharge protection diode and the light emitting diode are formed on the same chip, wherein the electrostatic discharge protection diode is connected in an anti-parallel configuration to the light emitting diode, such that the anode of the light emitting diode is connected to the cathode of the electrostatic discharge protection diode and the cathode of the light emitting diode is connected to the anode of the electrostatic discharge protection diode, for protecting the light emitting diode from damage by shunting current away from the light emitting diode when a reverse bias voltage above a threshold level is applied to the terminals of the light emitting diode, wherein the electrostatic discharge protection diode comprises a junction of N-type material and P-type material forming a PN junction, and wherein a metal layer portion (68, 80, 88, 92, 93) contacts the N-type material of the electrostatic discharge protection diode, characterised in that - an area of the substrate taken up by the electrostatic discharge protection diode is less than 30% of the total area taken up by the light emitting diode and the electrostatic discharge protection diode on the substrate, - a length of the PN junction of the electrostatic discharge protection diode is at least twice a width of the PN junction of the electrostatic discharge protection diode, and - a length of the metal layer portion (68, 80, 88, 92, 93) contacting the N-type material of the electrostatic discharge protection diode is at least 50% of the length of the PN junction of the electrostatic discharge protection diode.