A light emitting device (10) comprises a body (12) of a semiconductor material having a first face (14) and at least one other face (16) opposite to the first face. At least one pn-junction (18) in the body is located towards the first face and is reverse biased via contacts on the body into a light emitting mode, either in avalanche or field emission mode. The other face (16) of the body is configured to transmit from the body light emitted by the at least one pn-junction (18) in the near infrared part of the spectrum and having wavelengths longer than 1 mum.
