Organic light emitting device and method for mounting

The invention relates to a light source comprising a mounting substrate (125), one or more organic light emitting devices (100)mounted on the mounting substrate, each of the organic light emitting devices comprising a first electrode (130) which is light transmissive, an organic light emitting layer (110), a second electrode (120), a first device electrical contact extending from the first electrode (130) to the mounting substrate (125), and a second device electrical contact extending from the second electrode to the mounting substrate (125). The invention also relates to a method of making a light source comprising the steps of providing one or more organic light emitting devices (100), each of the organic light emitting devices having first and second device electrical contacts which have respective first and second device contacting surfaces which occupy a common plane, the first and second device electrical contacts being electrically connected with first and second electrodes(130,120) of the organic light emitting device, respectively, and mounting the organic light emitting devices (100) on a mounting substrate (125) such that the first and second device contacting surfaces make electrical contact with corresponding first and second mounting electrical contacts on the mounting substrate (125).