Heterostructure and light-emitting device employing the same

A multiple quantum well structure for a light emitting device or a photodetector, comprising alternately stacked AlGaN barriers and AlGaN wells, wherein a thickness of each of the AlGaN barriers and the AlGaN wells respectively satisfies:

• h
• i
• ≤
• -
• σ
• i
• 2
• ⁢
• ρ
• 0
• ⁢
• i
• ,
• where hi is the thickness of ith AlGaN barrier or well;
• σi is sheet charge density of a sheet of charge on a surface of the ith AlGaN barrier or well, the surface being oppositely charged in regard to net activated dopant in the ith AlGaN barrier or well;
• and
• ρ0i=eNDi−eNAi is maximal bulk charge density, allowed by applied doping concentration, in a depletion zone of the ith AlGaN barrier or well generated by the sheet of charge, NDi and NAi are donor and acceptor concentrations, respectively, in the ith AlGaN barrier or well, e is electric elementary charge.