A novel fused-droplet electrospray ionization (FD-ESI) source was developed to generate peptide and protein ions. The sample solution was first ultrasonically nebulized to form fine aerosols. The aerosols were then purged into a glass reaction chamber via nitrogen. Charged methanol droplets were continuously generated through electrospraying the acidic methanol solution from a capillary, which was located at the center of the reaction chamber. As the sample aerosols entered the reaction chamber, they fused with the charged methanol droplets from which electrospray proceeded continuously. The mass spectra of peptide and protein that FD-ESI-MS produced were practically identical to those that conventional ESI-MS produced. However, FD-ESI-MS resulted in an extremely high salt tolerance. Cytochrome c ions were detected in the solutions that contained 10% (w/w; 1.709 M) NaCl or 2.5% (425 mM) NaH2PO4. As with those obtained from the solution that lacked NaCl and NaH2PO4, the width of cytochrome c ion peaks remained nearly unchanged.

An ultrasonic nebulization/multiple channel electrospray ionization (USN/MC-ES) source, which generates multiply charged peptides and proteins ions, was developed. The source is an ultrasonic nebulizer that is connected to a multiple channel electrospray ionization source. Aerosols were formed by ultrasonically nebulizing the sample solution. The aerosols were then purged into the central channel of a seven-channel ES source via nitrogen gas. A methanol solution that contained 1% trifluroacetic acid was electrosprayed through the outlying six electrosprayers. Detection of multiply charged peptide and protein ions indicated that electrospray was generated from the charged droplet containing analyte. The sample aerosol appeared to fuse with the charged methanol droplet in the air. Then electrospray ionization of the analyte occurred from the newly formed droplet. The peptide and protein prepared in deionized water were detected by this USN/MC-ES-MS. By varying the electrospray solvents, the signals of certain components in the mixture were selectively suppressed.

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By correlating the various analytical results of Photo-Hall, Photoluminescence, and Differential Hall measurements with the stoichiometry, the related defect structure distributed in the forbidden gap of CuInS2 semiconductor in which the shallow levels were specified. We obtained four shallow donor levels are 11 meV, 18 meV, 31 meV and 38.5 meV and two more deep donor levels 70 meV and 145 meV below the conduction band edge for the n-CuInS2. The donor level located at 38.5 meV had been identified as sulfur vacancy, and other shallow levels were not identified. We also obtained that there are three acceptor levels as 0.11 eV, 0.155 eV and 0.17 eV above the valence band for the p-type CuInS2. The acceptor level located at about 0.105 eV and 0.155 eV above valence band had been identified. The acceptor level located at 0.17 eV above the valence band were also cognized by the Photo-Hall measurement. It could be identified such acceptor level as an electron trap.

The defect chemistry model is developed as a function of the nonmolecularity (Δ X) and nonstoichiometry (Δ Y), and the formation energies of defects are also considered. In this model, the p-type conductivity can occur in the region with Δ X<0 and Δ Y<0 and n-type conductivity can occur in the region with Δ X>0 and Δ Y>0. For above given regions, it could be possible to define a critical relation as Δ X c=8Δ Y/(1-2Δ Y). The p-type conductivity occurs in the Δ X (more negative value)<Δ X c region at a constant Δ Y value. As the decreasing of Δ X negative value, the type conversion appears near the Δ X equals to Δ X c region, and then it was dominated by n-type conductivity.