A diffusion heat treatment process for YBa₂Cu₃O_7-y bulk superconductor in a Gd₂O₃ powder was attempted. As a result of measuring the critical temperature of the superconducting bulk, there was no change in the superconducting transition temperature as the Gd particles diffused into the YBa₂Cu₃O_7-y lattice, resulting in dense microstructure. As a result of measuring the critical current, the critical current density (Jc) of the superconducting bulk having treated by the Gd thermal diffusion treatment at 0 T increased to 3×10⁴ A/㎠ at 0 T, which was higher than that of the superconducting bulk without thermal diffusion treatment. The surface magnetic force of the superconducting bulk with Gd thermal diffusion treatment was observed at the center of the superconducting bulk with the maximum trapped magnetic force (Hmax) of 1.51 kG. This result means that the Gd thermal diffusion treatment contributes to improving the critical current density Jc of YBa₂Cu₃O_7-y, and it is believed that Gd particles migrating into the superconducting bulk through thermal diffusion either fill the surface pores of YBa₂Cu₃O_7-y superconductors or act as a flux pinning center.

In this study, the physical mechanism and diffusion effects in aluminium implanted silicon was investigated. For fabricating power semiconductor devices, an aluminum implantation can be used as an emitter and a long drift region in a power diode, transistor, and thyristor. Thermal treatment with O₂ gas exhibited to a remarkably deeper profile than inert gas with N₂ in the depth of junction structure. The redistribution of aluminum implanted through via thermal annealing exhibited oxidation-enhanced diffusion in comparison with inert gas atmosphere. To investigate doping distribution for implantation and diffusion experiments, spreading resistance and secondary ion mass spectrometer tools were used for the measurements. For the deep-junction structure of these experiments, aluminum implantation and diffusion exhibited a junction depth around 20 μm for the fabrication of power silicon devices.

For the investigation of dopant profiles in implanted Si_1-xGe_x, the implanted B and As profiles are measured using SIMS (secondary ion mass spectrometry). The fundamental ion-solid interactions of implantation in Si_1-xGe_x are discussed and explained using SRIM, UT-marlowe, and T-dyn programs. The annealed simulation profiles are also analyzed and compared with experimental data. In comparison with the SIMS data, the boron simulation results show 8% deviations of R_p and 1.8% deviations of ΔR_p owing to relatively small lattice strain and relaxation on the sample surface. In comparison with the SIMS data, the simulation results show 4.7% deviations of R_p and 8.1% deviations of ΔR_p in the arsenic implanted Si_0.2Ge_0.8 layer and 8.5% deviations of R_p and 38% deviations of ΔR_p in the Si_0.5Ge_0.5 layer. An analytical method for obtaining the dopant profile is proposed and also compared with experimental and simulation data herein. For the high-speed CMOSFET (complementary metal oxide semiconductor field effect transistor) and HBT (heterojunction bipolar transistor), the study of dopant profiles in the Si_1-xGe_x layer becomes more important for accurate device scaling and fabrication technologies.

This research introduces the sputtered IZO thin film transistor (TFT) with solution-processed Al₂O₃ diffusion layer. IZO is one of the most commonly used amorphous oxide semiconductor (AOS) TFT. However, most AOS TFTs have many defects that degrade performance. Especially oxygen vacancy in the active layer. In previous research, aluminum was used as a carrier suppressor by binding the oxygen vacancy and making a strong bond with oxygen atoms. In this paper, we use a solution-processed Al₂O₃ diffusion layer to fabricate stable IZO TFTs. A double-layer solution-processed Al2O3-sputtered IZO TFT showed better performance and stability, compared to normal sputtered IZO TFT.

MOS-FET structured gas sensors were manufactured using MWCNTs for application as NOx gas sensors. As the gas sensors need to be heated to facilitate desorption of the gas molecules, heat dispersion plays a key role in boosting the degree of uniformity of molecular desorption. We report the desorption of gas molecules from the sensor at 150℃ for different sensor electrode gaps (30, 60, and 90 μm). The COMSOL analysis program was used to verify the process of heat dispersion. For heat analysis, structure of FET gas sensor modeling was proceeded. In addition, a property value of the material was used for two-dimensional modeling. To ascertain the degree of heat dispersion by FEM, the governing equations were presented as partial differential equations. The heat analysis revealed that although a large electrode gap is advantageous for effective gas adsorption, consideration of the heat dispersion gradient indicated that the optimal electrode gap for the sensor is 60 μm.

N-type crystalline silicon solar cells have high metal impurity tolerance and higher minority carrier lifetime that increases conversion efficiency. However, junction quality between the boron diffused layer and the n-type substrate is more important for increased efficiency. In this paper, the current status and prospects for boron diffused layers in N-type crystalline silicon solar cell applications are described. Boron diffused layer formation methods (thermal diffusion and co-diffusion using a-SiO_X:B), boron rich layer (BRL) and boron silicate glass (BSG) reactions, and analysis of the effects to improve junction characteristics are discussed. In-situ oxidation is performed to remove the boron rich layer. The oxidation process after diffusion shows a lower B-O peak than before the Oxidation process was changed into SiO₂ phase by FTIR and BRL. The a-SiO_X:B layer is deposited by PECVD using SiH₄, B₂H₆, H₂, CO₂ gases in N-type wafer and annealed by thermal tube furnace for performing the P+ layer. MCLT (minority carrier lifetime) is improved by increasing SiH₄ and B₂H₆. When a-SiO_X:B is removed, the Si-O peak decreases and the B-H peak declines a little, but MCLT is improved by hydrogen passivated inactive boron atoms. In this paper, we focused on the boron emitter for N-type crystalline solar cells.

In this study, the effect of Tb inward diffusion on the magnetic properties of the Nd-Fe-B sintered magnets was studied. After sintering of the magnets, TbF₃ slurries were dip-coated on the surface of the samples, then heat-treatment was followed for TbF₃ diffusion. The element distribution in the magnets and the diffusion profiles of Tb ions were analyzed by an EPMA (electron probe micro-analyzer). Prolonged heat treatment resulted in a deeper diffusion length of Tb ions. Coercivity of the 1^st heat-treated sample showed 21.86 kOe, while that of the 1^st, 2^nd heat-treated and annealed sample revealed 34 kOe.

For the formation of N+ doping, the antimony ions are mainly used for the fabrication of a BJT (bipolar junction transistor), CMOS (complementary metal oxide semiconductor), FET (field effect transistor) and BiCMOS (bipolar and complementary metal oxide semiconductor) process integration. Antimony is a heavy element and has relatively a low diffusion coefficient in silicon. Therefore, antimony is preferred as a candidate of ultra shallow junction for n type doping instead of arsenic implantation. Three-dimensional (3D) profiles of antimony are also compared one another from different tilt angles and incident energies under same dimensional conditions. The diffusion effect of antimony showed ORD (oxygen retarded diffusion) after thermal oxidation process. The interfacial effect of a SiO2/Si is influenced antimony diffusion and showed segregation effects during the oxidation process. The surface sputtering effect of antimony must be considered due to its heavy mass in the case of low energy and high dose conditions. The range of antimony implanted in amorphous and crystalline silicon are compared each other and its data and profiles also showed and explained after thermal annealing under inert N2gas and dry oxidation.

We have investigated the effects of spacer layer inserted between blue and red doped emissionlayers on the emission and efficiency characteristics of phosphorescent OLEDs. N,N``-di-carbazolyl-3,5-benzene(mCP) was used as a host layer. Iridium(III)bis[(4,6-di-fluorophenyl)- pyridinato-N,C2``]picolinate (FIrpic) andtris(1-phenyl-isoquinolinato-C2,N)iridium(III) [Ir(piq)3] were used as blue and red dopants, respectively. Theemission layer structure was mCP (1-x) nm/mCP:Ir(piq)3 (5 nm, 10%)/mCP (x nm)/mCP:FIrpic (5 nm, 10%). The thickness of mCP spacer layer was varied from 0 to 15 nm. The emission from Ir(piq)3 and theefficiency of the device were dominated by energy transfer from mCP host and FIrpic molecules, and bydiffusion of mCP host triplet excitons.