Budi Mulyanti

Determination of Thin Film Ba0.5Sr0.5TiO3 Ferroelectric Effective Mass from I-V Characteristics Calculation Using Transfer Matrix Method

In this paper, we present current-voltage model characterization calculation of Ba0.5Sr0.5TiO3 ferroelectric-based solar cell to determine its effective mass. Numerical calculation was done using Transfer Matrix Method (TMM). Fitting between the calculations results with experiment data can be done by approximating the Ba0.5Sr0.5TiO3 effective mass value. Ba0.5Sr0.5TiO3 effective mass can be obtained when both data fit.

Modeling of tunneling currents on Al/SiO2/p-Si MOS capacitors with nanometer-thick oxides

In this paper, the tunneling current calculations of isotropic and anisotropic-isotropic electron effective mass on Al/SiO2/p-Si MOS involving coupling effect are presented. The results indicated that the impact of tunneling calculation involving coupling effect is that electron velocity acts as parameter of calculation, especially in inversion condition. In this condition, the difference between anisotropic-isotropic and isotropic calculation results tends to be greater when the electron velocity increases. The result of anisotropic-isotropic model is closer to the theory than that of isotropic result. In addition, the coupling effect makes the values of tunneling current more sensitive to the electron effective mass.

Plasma-assisted MOCVD growth of GaMnN

The growth of GaMnN thin films on c-plane sapphire substrate by plasma-assisted metalorganic chemical vapor deposition (PAMOCVD) method is reported. Cyclopentadienyl manganese tricarbonyl (Cp2MnT) was used as a source of Mn. The growth was conducted at varied growth temperature in the range of 625 to 700°C and V/III flux ratios between 440 and 1080. The growth rate and Mn incorporation into GaN highly depend on growth parameters. From the analysis of XRD spectra, it was found that the highest Mn incorporation into GaMnN which would produce single phase GaMnN (0002) was 6.4 % at growth temperature of 650°C. While at growth temperature of 700°C, the maximum of Mn incorporation into GaMnN films that would still produce single phase film were 3.2 %. The surface roughness of the films determined from AFM image results showing that high growth temperatures tend to improve the surface morphology of GaMnN. The results of magnetization measurement shows hysteresis behavior at room temperature with various values of coercivity, saturation and remnant magnetization in the range of 350-800 Oe, 20-39 emu/cm3 and 10.2–34.4 emu/cm3, respectively depend on the Mn concentration. For the films grown at 650 °C, the highest magnetic moment per Mn-atom was obtained by a sample with Mn concentration of 2.0 %, i.e. 3.1 µΒ/Mn-atom. While for the films grown at 700°C, the highest magnetic moment per Mn-atom was obtained by a sample with Mn concentration of 2.5 %, i.e. 3.7 µΒ /Mn-atom.