A method for the determination of optimum p-n junction depth of luminescence devices

Theoretical calculations show that for maximum output power of LED’s an optimal ratio between the p-n junction depths and the diffusion lengths of minority carriers of 2–3 is required. A method based on the photoluminescence technique is described which allows the determination of the a/L ratio. Measurements on various types of luminescence diodes were carried out. In double-heterostructure lasers diffusion lengths in the range 1.2–4.6 μm were estimated.