A STUDY OF PBSE HETEROEPITAXY ON SI(111) FOR IR OPTOELECTRONIC APPLICATIONS

Molecular beam epitaxy was used to grow heteroepitaxial PbSe on Si(111) substrates with the aid of BaF2 and CaF2 buffer layers. The growth process was optimized with respect to transmission electron microscopy, atomic force microscopy and X-ray diffraction characterizations. A careful understanding of the initial stages of CaF2/Si(111) growth allows the buffer layer thickness to be reduced to less than 100 Angstrom, which definitely improves the compatibility of such structures with standard photolithographic technological procedures. Preliminary photovoltaic sensor performances are very promising for the use of such devices in non-cryogenically cooled conditions.