Radiation-emitting semiconductor chip, optoelectronic component comprising a radiation-emitting semiconductor chip, and method of coating a radiation-emitting semiconductor chip

1. A radiation-emitting semiconductor chip comprising:

a substrate;

an epitaxial semiconductor layer sequence having an active zone that generates electromagnetic radiation of a first wavelength range, wherein the substrate is transparent to electromagnetic radiation of the active zone; and

an optically active layer arranged on a side surface of the substrate and on a rear main surface of the semiconductor chip, which lies opposite to a radiation exit surface of the semiconductor chip, wherein the optically active layer is a Bragg mirror that absorbs radiation of the active zone in a targeted manner over the entire first wavelength range.

2. The radiation-emitting semiconductor chip according to claim 1 , wherein the optically active layer is applied over the entire surface to rear main surface of the semiconductor chip and is applied over the entire surface to the side surface of the substrate.

3. The radiation-emitting semiconductor chip according to claim 1 , wherein a region of the side surface of the substrate adjoining a rear main surface thereof is covered continuously with the optically active layer, while a further region of the side surface of the substrate is free of the optically active layer.

4. The radiation-emitting semiconductor chip according to claim 1 , wherein the thickness of the optically active layer on the side surface of the substrate decreases from the rear main surface towards a radiation exit surface.

5. The radiation-emitting semiconductor chip according to claim 1 , wherein which the radiation exit surface is provided with an absorption layer that absorbs radiation of the active zone in a targeted manner to adjust the brightness of the semiconductor chip to a desired value.

6. The radiation-emitting semiconductor chip according to claim 1 , wherein a highly reflective Bragg mirror that reflects radiation of the active zone is applied on the rear main surface of the substrate.

7. An optoelectronic component comprising a semiconductor chip, said semiconductor chip comprising:

a substrate;

an epitaxial semiconductor layer sequence having an active zone that generates electromagnetic radiation of a first wavelength range, wherein the substrate is transparent to electromagnetic radiation of the active zone; and

an optically active layer arranged on a side surface of the substrate and on a rear main surface of the semiconductor chip, that lies opposite to a radiation exit surface of the semiconductor chip, wherein

the semiconductor chip is surrounded by a conversion element that converts radiation of the first wavelength range into radiation of at least one other wavelength range, and

the optically active layer transmits unconverted radiation of the first wavelength range and reflects at least partially converted radiation of the at least one other wavelength range.

8. A radiation-emitting semiconductor chip comprising:

a substrate;

an epitaxial semiconductor layer sequence having an active zone that generates electromagnetic radiation of a first wavelength range, wherein the substrate is transparent to electromagnetic radiation of the active zone; and

an optically active layer arranged on a side surface of the substrate and on a rear main surface of the semiconductor chip, which lies opposite to a radiation exit surface of the semiconductor chip, wherein the optical active layer is a single semiconductor layer that absorbs radiation of the active zone.