A semiconductor light source having a primary radiation source, the primary radiation source comprising a semiconductor chip, which emits electromagnetic primary radiation during operation of the semiconductor light source, and comprising a luminescence conversion module into which at least a part of the primary radiation is coupled, wherein - the luminescence conversion module contains a luminescence conversion element which converts at least part of the coupled primary radiation into a secondary radiation by means of at least one phosphor, - the luminescence conversion module is arranged at a distance from the primary radiation source on a heat sink, - the luminescence conversion element is in the form of a substantially planar layer or plate, the surface of which has a first major surface representing a light-outcoupling surface, a second major surface opposite the first major surface and facing the heat sink, and at least one side surface, - during operation, the primary radiation is coupled into the luminescence conversion element through the first major surface or through the side surface, - the luminescence conversion module comprises a reflector layer (7, 71, 72), - the reflector layer (7, 71, 72) reflects the primary radiation, which passes through the luminescence conversion element and is not absorbed therefrom, back into the luminescence conversion element and reflects the secondary radiation in the direction of the light-outcoupling surface of the luminescence conversion module, - a first partial region of the reflector layer (7, 71, 72) is arranged between the luminescence conversion element and the heat sink, - a second partial region of the reflector layer (7, 71, 72) at least partially covers the side surface of the luminescence conversion element. - the luminescence conversion module contains a luminescence conversion element which converts at least part of the coupled primary radiation into a secondary radiation by means of at least one phosphor, - the luminescence conversion module is arranged at a distance from the primary radiation source on a heat sink, - the luminescence conversion element is in the form of a substantially planar layer or plate, the surface of which has a first major surface representing a light-outcoupling surface, a second major surface opposite the first major surface and facing the heat sink, and at least one side surface, - during operation, the primary radiation is coupled into the luminescence conversion element through the first major surface or through the side surface, - the luminescence conversion module comprises a reflector layer (7, 71, 72), - the reflector layer (7, 71, 72) reflects the primary radiation, which passes through the luminescence conversion element and is not absorbed therefrom, back into the luminescence conversion element and reflects the secondary radiation in the direction of the light-outcoupling surface of the luminescence conversion module, - a first partial region of the reflector layer (7, 71, 72) is arranged between the luminescence conversion element and the heat sink, - a second partial region of the reflector layer (7, 71, 72) at least partially covers the side surface of the luminescence conversion element.