Deep Level Transient Spectroscopy (DLTS) reveals three electrical levels of substitutional nickel in silicon at EC – 0.07 eV, EC – 0.45 eV, and EV + 0.16 eV. A number of additional DLTS peaks are observed after hydrogenation of the samples. We identify different NiHx -complexes with x = 1, 2, and 3. NiH introduces a single acceptor and a single donor state at about EC – 0.17 eV and EV + 0.49 eV into the band gap of silicon. NiH2 and NiH3 are shown to have a single acceptor state at EV + 0.58 eV and EV + 0.46 eV, respectively. In addition to the electrically active NiHx-complexes, a total passivation of the electrical activity of nickel by hydrogen is observed.

n-type float-zone silicon grown in a nitrogen atmosphere contains defects which are activated by temperatures between 450 and 700 °C. We use deep level transient spectroscopy (DLTS) to study the nature of these defects and the impact of the nitrogen content and the polysilicon feed stock type. We find four dominant DLTS peaks with activation energies of Ena = 0.16 eV (E1), Ena = 0.21 eV (E2), Ena = 0.34 eV (E4), and Ena = 0.64 eV (E6). We tentatively assign the two DLTS peaks E1 and E2 to single acceptor and single donor levels of the same defect, a complex of nitrogen with an impurity. Furthermore, we tentatively assign the two DLTS peaks labeled E4 and E6 to two levels of the off-center substitutional nitrogen. Based on the apparent electron capture cross sections and an analysis of the electric field effect on the emission rates, we propose them to be double and single acceptor levels, respectively. Due to its position at midgap and the competing electron and hole emission, the apparent concentration of E6 is reduced to one fifth of the total defect concentration. Correcting for these processes, we find the activation energies for electron and hole emission to be En = 0.50 eV and Ep = 0.68 eV.

In the present study single-crystalline ZnO samples grown from the vapor phase, the melt, and a high-temperature aqueous solution (hydrothermal growth) are investigated before and after hydrogen plasma treatments, by means of deep level transient spectroscopy (DLTS) and high-resolution Laplace DLTS. Dominant DLTS peaks are found to appear in the range of 120-350 K for all materials. The DLTS spectra depend on the procedure of growth of the ZnO. The thermal stabilities of the defects in an oxygen atmosphere and in an oxygen-lean atmosphere are analyzed. The origin of the DLTS peaks is discussed.

Using high-resolution Laplace deep level transient spectroscopy studies, several TiH-related complexes (E40′, E170, E170′, and E260) were observed in wet-chemically etched and H-plasma treated n-type Si. We assign E40′ and E170 to two different configurations of Ti with one H atom. Both of them are shown to behave as single donor states with an activation enthalpy of EC − 0.07 eV (E40′) and EC − 0.34 eV (E170) in the upper half of Si. E170′ with an activation energy of EC − 0.37 eV is correlated with the donor state of the TiiH2 defect, whereas E260 is attributed to the donor state of TiiH3. Besides the TiH defects, the presence of electrically inactive TiH4 is reported. No titanium-hydrogen-related levels were observed in p-type Si.

Two dominant peaks at EC − 0.39 eV and EV + 0.46 eV previously assigned to substitutional cobalt are shown to belong to different defects by high-resolution Laplace Deep Level Transient Spectroscopy. We assign the level in the upper half of the band gap to substitutional Cos, whereas the level in the lower half is attributed to a CoB pair. No electrically active levels which belong to interstitial Coi was found. Besides the dominant defects, a number of minor DLTS peaks were observed. We correlate these peaks with H-related defects and will also discuss their origin.