Characterization and growth of high quality ZnTe epilayers by hot-wall epitaxy

Photoluminescence of ZnTe and ZnTe:Cr grown by molecular-beam epitaxy

“…The first phonon replica of the A 1 peak appears at 2.3431 eV, separated in energy by 26 meV (i.e., the LO-phonon energy) from A 1 , and is indicated by an asterisk. This line has been observed by many groups [3][4][5]7,[9][10][11][12][13] and has been attributed to a column-IV double acceptor 3,4,7 or to lattice defects such as V Zn . This assignment indicates that trace amounts of arsenic from the GaAs substrate have diffused into the II-VI layer and formed As Te acceptors.…”

“…Its band gap is about 2.25 eV at room temperature and 2.3941 eV at 1.6 K. 1 Many groups have reported photoluminescence (PL) from ZnTe films grown on GaAs. [2][3][4][5]7,[9][10][11][12] There has been some debate about the origin of excitonic bands near 2.375 and 2.379 eV at 5 K. The emission observed near 2.375 eV has been attributed only to the light-hole exciton ͑X lh ͒, 4,7-9,11,12 to a superposition of ͑D 0 , X͒ and ͑D 0 , h͒, 3 or to a superposition of ͑D 0 , X͒ and X lh . [2][3][4][5]7,[9][10][11][12] There has been some debate about the origin of excitonic bands near 2.375 and 2.379 eV at 5 K. The emission observed near 2.375 eV has been attributed only to the light-hole exciton ͑X lh ͒, 4,7-9,11,12 to a superposition of ͑D 0 , X͒ and ͑D 0 , h͒, 3 or to a superposition of ͑D 0 , X͒ and X lh .…”

“…[2][3][4][5][6][7][8][9][10][11][12][13] Because of the mismatches in thermal coefficients and lattice constants between the thin film and substrate, elastic-strain shifts in excitonic emission lines must be considered when making transition assignments. 5,13 The band near 2.379 eV has been assigned to the heavy-hole exciton 4,5,[7][8][9][11][12][13] or to a close superposition of the heavy-hole and light-hole excitons. 5,13 The band near 2.379 eV has been assigned to the heavy-hole exciton 4,5,[7][8][9][11][12][13] or to a close superposition of the heavy-hole and light-hole excitons.…”

Evaluation of crystal structure and photoluminescence for ZnTe epilayers grown on a 2o off‐oriented GaAs (100) substrate

“…This could be interpreted to mean that the Zn and Te atoms occupy the stable lattices sites, because adatoms for ZnTe growth increase mobility on the surface as the growth temperature increases. For ZnTe epitaxial layers grown on a tilted GaAs (100) substrate, the best FWHM value was approximately 200 arcsec at 470 °C, which was slightly smaller than the value of ZnTe epilayers with the same thickness grown on an exact GaAs (100) substrate under optimum growth conditions [6]. However, the FWHM value of DCRC abruptly becomes broader at a growth temperature of 480 °C.…”

“…This heteroepitaxial structure has a lattice mismatch, differences in the thermal expansion coefficients, and different chemical properties. These aspects may detrimentally affect the crystallinity due to crystal defects generated at the interface [6,7].…”