| 摘要 |
PURPOSE:To obtain a semiconductor element provided with a quantum well structure which is free from the restriction imposed by a forbidden bandwidth peculiar to a material by method wherein a material, whose lattice constant is different from that of the main material which forms a quantum well layer, is arranged inside the quantum well layer. CONSTITUTION:Quantum well layers 3 and 9 are formed of a GaAs light emitting layer 3 of a first main materiel and an Al InSb layer 9 of a second material whose lattice constant is different from that of GaAs. An n-type AlGaAs layer 7 and a p-type AlGaAs layer 8 serve as light trapping layers, whose compositional ratios of Al are larger than those of AlGaAs layers 2 and 4 and which have compositions of a low refractive index. The layers 3 and 9 have nearly the same forbidden bandwidth which is much different from that of the lattice constant layer 3. Provided that the thickness of the layer 9 is 31Angstrom , 5 times a period of the lattice constant, a phase shift occurs between the layers 3 and 9 by a half lattice of a lattice arrangement, an energy level 203 occurs at a halfway point in the forbidden band, and the transition of electrons is generated through the energy level 203 or electrons and holes are recombined with each other, so that light of energy half a quantum well inter-level energy of electrons and holes is emitted as emitted photons 302. |
