Attainment crystalline films for manufacturing thermal infrared optoeletronic detectors

Resumo

The project has as objective to make the system of epitaxial growth Hot Wall Beam Epitaxy (HWBE) enter in operation for the attainment of compound semiconductors IV-VI family single crystalline films, over barium fluoride (BaF2) substrates. This called epitaxial system (HWBE) is the technique that involves physical transport and works next to the thermodynamics equilibrium. Its main function is the growth of single crystalline films, which by the choice of the compounds they behave as photonic crystals. The advantage in the use of BaF2 as substrate is its good marriage of the crystallographic arrangement and thermal expansion coefficient with the compound film used, that are: lead telluride (PbTe), chosen because they possess optic properties, high quantum efficiency and mainly the energy of the forbidden band - band gap (Eg) is direct and narrow (Eg < 270meV). It can thus be used as P-N junctions, which are the infrared detectors that work with the wavelength (λ) range - 5 µm.