| Abstract [eng] |
The last decade huge interest in devices, operating in telecommunication wavelengths window (from 1 μm to 1.5 μm) was observed. Traditionally the active area of such components is fabricated using heterostructures of A3-B5 semiconductor compounds. These devises are sensitive to temperature, and stabilization of parameters require external coolers. To obviate disadvantages and fulfill the main requirements for semiconductors technologies - high efficiency and low costs, the performances of components must be improved. This could be achieved replacing usual heterostructures by new more attractive material. Theoretic outlook of bismide compounds attracts attention of scientists working in both material engineering as well research and commercial device application directions. This study aims to growth technology and complex investigation of multiple quantum well (MQW) structures for LEDs exhibiting luminescent properties in spectral range from 1 μm to 1.5 μm. A new concept of LED design was proofed. Combining two earlier demonstrated by our group ideas [22, 23], pin structures with insulating layer containing Bi quantum dots in the wells sandwiched by parabolic quantum barriers were fabricated. The optimization of MQWs was performed by MBE, varying Bi content, QW and barrier thickness, in-situ annealing temperature and time. Photoluminescence and voltage-current measurements of MQW structures and LEDs have been carried out to evaluate the optical and electrical properties and served as a feed-back for epitaxy optimum conditions mapping. The complex characterization of samples permitted to reveal the dominating recombination mechanisms in bismides MQWs, and define key parameters influencing to LEDs performances. The idea of combination of AlAs tunnel barriers, parabolic QW and in situ thermal annealing was proved. LED based on Bi-QDs in GaAsBi QWs demonstrated the emission from 1050 nm to 1250 nm. |
