Low temperature characterization of modulation doped SiGe grown on bonded silicon-on-insulator

Modulation doped pseudomorphic Si0.87Ge0.13 strained quantum wells were grown on bonded silicon-on-insulator (SOI) substrates. Comparison with similar structures grown on bulk Si(100) wafers shows that the SOI material has higher mobility at low temperatures with a maximum value of 16 810 cm 2/V s for 2.05 × 1011 cm – 2 carries at 298 mK. Effective masses obtained from the temperature dependence of Shubnikov–de Haas oscillations have a value of (0.27 ± 0.02) m0 compared to (0.23 ± 0.02) m0 for quantum wells on Si(100) while the cyclotron resonance effective masses obtained at higher magnetic fields without consideration for nonparabolicity effects have values between 0.25 and 0.29 m0. Ratios of the transport and quantum lifetimes, tau/tau q=2.13 ± 0.10, were obtained for the SOI material that are, we believe, the highest reported for any pseudomorphic SiGe modulation doped structure and demonstrates that there is less interface roughness or charge scattering in the SOI material than in metal–oxide–semiconductor field effect transistors or other pseudomorphic SiGe modulation doped quantum wells

Reading Culture, Parental Involvement and Children’s Development in Formative Years: The Covenant University Experience

Reading culture and parental involvement in the development of children in their formative years are the most crucial factors which form the foundation for the child‘s education. This study examines these two key factors, while the respondents for the study were confined to the Covenant University. The research concentrates on reading culture at the formative years of the children (from birth to age 7) and the degree of parental involvement in the child’s development. In order to make an assessment of the current reading culture of the children in the academic community, a survey of 211 parents, comprising 115 fathers (54.4%) and 96 mothers (45.49%) was conducted. This study showed that the practice of early childhood reading among parents in Covenant University is high (95.2%) and the respondents have a good perception on the need and importance of early childhood reading. However, there is evidence to show that there is poor habit of borrowing books from libraries. This trend has a direct negative impact on inculcating reading culture in their children. Most of the respondents (87.7%) are of the opinion that learning activities provided by nursery school are not sufficient for children’s development without parental involvement. On the average, parents spend at least one hour reading to their children, but mainly during the weekends. The availability of time is a major obstacle faced by parents in cultivating reading culture for their children in (83.4%) of cases, while lack of parental involvement account for (23.3%). Only (3.3%) of the respondents thought reading to children is a waste of time. Based on the results of the study appropriate recommendations were made

Design and performance of a prototype mesa-geometry Ge-on-Si single-photon avalanche diode detector at 1310 nm and 1550 nm wavelengths

Ge-on-Si single-photon detectors are fabricated and characterized at 1310 and 1550 nm. 4 % single-photon detection efficiency is observed at 1310 nm demonstrating the lowest reported noise equivalent power for Ge-on-Si single-photon detectors (1×10-14 WHz-1/2)