Luminescence of n-i-p-i heterostructures

The luminescence properties of a new superlattice structure, called a n-i-p-i heterostructure, are described. The samples consist of GaAs quantum wells placed between alternately doped ${\mathrm{Al}}_{1\mathrm{-}\mathrm{x}}$ ${\mathrm{Ga}}_{\mathrm{x}}$As layers. The luminescence transitions between the quantized GaAs subbands are greatly influenced by the excitation-intensity-dependent electrostatic potential. The lowest subband luminescence transition agrees well with predictions for the ideal structure. In addition, distinct luminescence transitions from higher subbands are observed.