ZnS epilayers were grown by pyrolytic OMVPE using diethyldisulfide (Et2S2) as S alkyl precursor in conjunction with dimethylzinc-triethylammine. Et2S2 lowers the temps. of the process by ∼150° with respect to Et2S, leading to growth rates around 0.5 μm/h just >400°. Mass spectrometry measurements allowed to det. the Et2S2 relative bond strengths by looking at the fragmentation path of Et2S2+. The S-S bond is stronger than the S-C bonds in the Et2S2 mol., possibly leading to a destabilization of the latter, which finally results into lower pyrolysis temps. for the alkyl. 10 K cathodoluminescence (CL) spectra of ZnS show both free-to-bound and intense self-activated bands peaked at 3.683 eV and 2.58 eV, resp. These emissions are attributed to unintentional Na and halogen (most probably Cl) doping of ZnS epilayers. Monochromatic CL images of ZnS samples evidenced the interplay between point-defects induced radiative emissions and nonradiative recombinations assocd. to the ZnS extended defects.
Low temperature MOVPE growth and characterization of ZnS using diethyldisulfide as sulfur precursor
MELE, Giuseppe Agostino;VASAPOLLO, Giuseppe;
1998-01-01
Abstract
ZnS epilayers were grown by pyrolytic OMVPE using diethyldisulfide (Et2S2) as S alkyl precursor in conjunction with dimethylzinc-triethylammine. Et2S2 lowers the temps. of the process by ∼150° with respect to Et2S, leading to growth rates around 0.5 μm/h just >400°. Mass spectrometry measurements allowed to det. the Et2S2 relative bond strengths by looking at the fragmentation path of Et2S2+. The S-S bond is stronger than the S-C bonds in the Et2S2 mol., possibly leading to a destabilization of the latter, which finally results into lower pyrolysis temps. for the alkyl. 10 K cathodoluminescence (CL) spectra of ZnS show both free-to-bound and intense self-activated bands peaked at 3.683 eV and 2.58 eV, resp. These emissions are attributed to unintentional Na and halogen (most probably Cl) doping of ZnS epilayers. Monochromatic CL images of ZnS samples evidenced the interplay between point-defects induced radiative emissions and nonradiative recombinations assocd. to the ZnS extended defects.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
