Carbon incorporation in ZnSe grown by metalorganic chemical vapor deposition

Carbon incorporation in ZnSe films grown by metalorganic chemical vapor deposition is reported. Secondary‐ion mass spectrometry measurements in ZnSe films grown from methylallylselenide and dimethylzinc show an enhanced carbon accumulation at the interface between ZnSe and GaAs. The carbon incorporation in the bulk ZnSe increases with the VI/II ratio and for a value of VI/II=3–4, the amount of incorporated carbon abruptly jumps to concentrations of 10^(21) cm^(−3), whereupon the films become polycrystalline. A new shallow peak I^C at 2.7920 eV dominates the near‐band‐edge low‐temperature photoluminescence spectra of all carbon‐contaminated ZnSe films. The intensity and linewidth of I^C increase with the VI/II ratio in a similar manner to the carbon concentration. This peak is proposed to be due to the radiative decay of excitons bound to a complex defect, which is associated with the presence of carbon in the films

Postacquisition Mass Resolution Improvement in Time-of-Flight Secondary Ion Mass Spectrometry

Good mass resolution can be difficult to achieve in time-of-flight secondary ion mass spectrometry (TOF-SIMS) when the analysis area is large or when the surface being analyzed is rough. In most cases, a significant improvement in mass resolution can be achieved by postacquisition processing of raw data. Methods are presented in which spectra are extracted from smaller regions within the original analysis area, recalibrated, and selectively summed to produce spectra with higher mass resolution than the original. No hardware modifications or specialized instrument tuning are required. The methods can be extended to convert the original raw file into a new raw file containing high mass resolution data. To our knowledge, this is the first report of conversion of a low mass resolution raw file into a high mass resolution raw file using only the data contained within the low mass resolution raw file. These methods are applicable to any material but are expected to be particularly useful in analysis of difficult samples such as fibers, powders, and freeze-dried biological specimens

Fluorine Plasma Treatments of Polypropylene Films, 1 – Surface Characterization Part 2: cf. ref. 11

In this work, an experimental investigation of fluorine gas (F 2 ) plasma treatment of polypropylene (PP) film reveals the evolution of PP fluorination. Surface analysis of fluorinated PP surfaces describes a surface modification process that is initially quite rapid but slows sharply as the fluorination progresses. The fluorination reaction occurs more rapidly at the PP film surface and evidence of a treatment gradient is seen in the ESCA sampling depth of 10 nm. The increasingly fluorinated surface becomes less reactive to the plasma chemistry and develops a fully fluorinated, cross-linked surface layer that eventually extends the full ESCA sampling depth.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65033/1/107_ftp.pd