CHARACTERIZATION OF AN ALGAAS GAAS ASYMMETRIC TRIANGULAR QUANTUM-WELLGROWN BY A DIGITAL ALLOY APPROXIMATION/

An asymmetric triangular quantum well was grown by molecular-beam epit axy using a digital alloy composition grading method. A high-resolutio n electron micrograph (HREM), a computational model, and room-temperat ure photoluminescence were used to extract the spatial compositional d ependence of the quantum well. The HREM micrograph intensity profile w as used to determine the shape of the quantum well. A Fourier series m ethod for solving the BenDaniel-Duke Hamiltonian [D. J. BenDaniel and C. B. Duke, Phys. Rev. 152, 683 (1966)] was then used to calculate the bound energy states within the envelope function scheme for the measu red well shape. These calculations were compared to the E11h, E11l, an d E22l transitions in the room-temperature photoluminescence and provi ded a self-consistent compositional profile for the quantum well. A co mparison of energy levels with a linearly graded well is also presente d.