Point defects in BaSi2 thin films for photovoltaic applications studied by positron annihilation spectroscopy

Abstract

Point defects in BaSi 2 thin films for photovoltaic applications studied by positron annihilation spectroscopy.

Realizing the Potential of RF-Sputtered Hydrogenated Fluorine-Doped Indium Oxide as an Electrode Material for Ultrathin SiOx/Poly-Si Passivating Contacts

“…film denotes an S – W reference point, and error bars were calculated as the average deviation of fitted values to measured data in the energy range of 1–2.5 keV where the targeted IFO:H film is probed (see Supporting Information, Figure S2 and Table S1). Specifically, the S -parameter provides sensitivity to the presence of open-volume defects, while the W -parameter is more dependent on the type of atoms surrounding the annihilation site. , From Figure a, the S -parameter of the N 2 -ann. layer and of the as-dep.…”

“…Further, the presence of open-volume defects was studied by Doppler broadening positron annihilation spectroscopy (DB-PAS) using the mono-energetic low-energy positron beam VEP at Delft University of Technology. 38 A liquid nitrogen-cooled high-purity Ge (HPGe) detector with an energy resolution of 1.3 keV was utilized to determine the energy of the emitted positron-electron annihilation γrays. The line shape parameter S was calculated as the ratio of the central region (|ΔE| < 0.8 keV) of the 511 keV annihilation γ-ray photopeak to the total area, and the wing parameter W was defined as the ratio of wing regions (2.1 keV < |ΔE| < 6.0 keV) to the total area.…”

“…Further, the presence of open-volume defects was studied by Doppler broadening positron annihilation spectroscopy (DB-PAS) using the mono-energetic low-energy positron beam VEP at Delft University of Technology . A liquid nitrogen-cooled high-purity Ge (HPGe) detector with an energy resolution of 1.3 keV was utilized to determine the energy of the emitted positron-electron annihilation γ-rays.…”

“…The line shape parameter S was calculated as the ratio of the central region (|Δ E| < 0.8 keV) of the 511 keV annihilation γ-ray photopeak to the total area, and the wing parameter W was defined as the ratio of wing regions (2.1 keV < |Δ E| < 6.0 keV) to the total area. The Doppler depth profiles collected in the range of 0.1–24 keV were fitted to extract S and W parameters of corresponding samples using the VEPFIT program . The extracted thicknesses of IFO:H films from VEPFIT analysis were approximately 280, 280, 80, and 80 nm for as-dep., N 2 -ann., H 2 -ann., and air-ann.…”

Recent Progress Toward Realization of High‐Efficiency BaSi2 Solar Cells: Thin‐Film Deposition Techniques and Passivation of Defects

“…analyzing the data from photoluminescence, [53,83,84] deep-level transient spectroscopy (DLTS), [85] positron annihilation spectroscopy, [86] and electron paramagnetic resonance [87] measurements. As a result, a scheme of the defect-level positions has been proposed on the basis of radiative defects (Figure 9).…”