The structural and optical characterization of thin-film ZnTe/CdSe heterojunctions

The thin-film ZnTe/CdSe heterojounctions were prepared onto glass substrates covered with a transparent conducting SnO2 layer. ZnTe (d=74-771 nm) and CdSe (d=843-1322 nm) thin films were deposited by thermal evaporation (cvasi-closed volume technique) under vacuum. Deposition conditions: deposition rate r(d)=15 angstrom/s; substrate temperature, T-s=300 K-500 K; source temperature, T-ev=1000 K-1300 K. Structural investigations, performed by X-ray diffraction technique, and atomic force microscopy, showed that studied samples are polycrystalline and have a zinc blende (ZnTe) or wurtzite (CdSe) structure. Transmission and absorption spectra were studied (in the spectral range 300-1400 nm) both for component films and heterojounctions.