Screening of quantum-confined Stark effect in nitride laser diodes and superluminescent diodes

In the present work we report on the observation of carrier-induced screening of built-in electric fields in (Al, In)GaN laser diodes and superluminescent diodes. We use the emission peak energy as a measure of the quantum-confined Stark effect and its screening by free carriers. For superluminescent diodes we observe a steady increase of screening up to the current density of 10 kA cm−2. This shows that the lasing in nitride laser diodes occurs under high electric fields, far from the flat band conditions.