Ex) Article Title, Author, Keywords
Abstract : Hexagonal Si-AlN core-shell microcrystals were grown by the mixed-source hydride vapor phase method. In particular, it was found that the hexagonal Si-AlN core-shell microcrystals were grown by the role of the Al-based nanostructure. Since hexagonal Si has a quasi-direct bandgap energy and AlN also has a hexagonal wurtzite structure, it can open up new opportunities for power semiconductors or optoelectronic devices. In this paper, the hexagonal Si-AlN core-shell microcrystals grown were characterized using scanning electron microscopy (FE-SEM), EDS and HRTEM, and the growth mechanism is presented. Therefore, the hexagonal Si-AlN core-shell microcrystal is expected to be an example of a new method in the field of semiconductor growth.
Abstract : Optoelectronic properties of a phototransistor made from solution-processed amorphous InGaZn oxide (a-IGZO) were investigated. This wide bandgap metal oxide semiconductor is known for its optical transparency, yet it exhibits visible light absorption attributed to sub-gap states resulting from oxygen vacancies. The study found that depositing a thin layer of aluminum oxide (AlOx) on the transistor channel led to an increase of photocurrent in the visible spectrum. Additionally, surface treatment of the a-IGZO thin film with UV ozone reduced persistent photoconductivity at 450 nm. Analysis of the absorption coefficient and optical band gap indicated that the results were associated with changes in the oxygen vacancy states within the a-IGZO thin film. The ability to control photocurrent and persistent photoconductivity through the deposition of aluminum (Al) and UV ozone treatment opens up exciting possibilities for applications in photosensors and neuromorphic systems.
Abstract : An atomic force microscope (AFM) is a powerful analytical tool for many ﬁelds of science and engineering. Despite its usefulness, the actual instrument is highly technical and expensive, rendering it inaccessible to a majority of practitioners in science and engineering education. Growing curiosity of students through the hands-on learning method is appealing to education managers. Adoption of LEGO® or similar educational kits into a school environment can not only fascinate the interests of students for learning but also resolve the cost problems. Our conceptual AFM system constructed with LEGO® Education SPIKETM Prime kit is very much suitable for explaining the principles behind the workings of an AFM while promoting students interests in experimental aspects of scientiﬁc instrumentation.
Abstract : In this study, mode-locking condition analysis was conducted on an optical ﬁber laser with λ/4 plate, λ/2 plate, and polarizer sequentially installed inside for mode-locked pulse generation via the nonlinear polarization rotation eﬀect in the optical ﬁber. To examine the rotation angle conditions of wave plates where mode-locked pulses occur, an experiment was conducted to measure the polarization state of the beam at the optical ﬁber’s resonator end. The results were employed to acquire a transmittance map of the output coupler based on the rotation angles of the wave plates. The correlation between the measured mode-locking region and the obtained transmittance of the output coupler was analyzed based on the rotation angles of the wave plates. The ﬁndings revealed that the rotation angle region of the wave plates where mode-locked pulses occur can be easily observed on the transmittance map.
Abstract : Using a scaling analysis of statistical physics, this study quantitatively reveals the relationship between department and freshman densities by majors in Korean higher education institutions against the regional school-age population density. In particular, we deﬁne a scaling exponent that quantiﬁes differences in department and freshman densities in accordance with the differences in the regional school-age population density. We also discuss the regional differences in higher education with the temporal change of the exponent. The scaling exponents of junior colleges are higher than those of universities. Moreover, the scaling exponents of basic natural science, education, and medical–pharmaceutical majors are smaller than those of others. The exponents of freshman density increase over time in all disciplines, implying increasing regional differences in higher education. Finally, the ﬁndings can be extended to a more systematic study to plan the coexistence of balanced development with regional communities.
Aekyung Shin, Donggeul Hyun, Jeongwoo Park
New Phys.: Sae Mulli 2023; 73(1): 37-43
Sangwoo Ha, Hunkoog Jho
New Phys.: Sae Mulli 2022; 72(4): 319-328
Geon Park, Inseo Kim, Hojung Sun, Yongjei Lee, Kimoon Lee, JungYup Yang
New Phys.: Sae Mulli 2023; 73(1): 23-28