Formation of β-Bi2O3 and δ-Bi2O3 during laser irradiation of Bi films studied in-situ by spatially resolved Raman spectroscopy

Abstract

The formation of different phases of Bi 2 O 3 induced by laser irradiation of Bi films has been assessed in situ by micro-Raman spectroscopy as a function of laser wavelength, power density and irradiation time. Raman mapping of the irradiated samples enabled a spatially-resolved study of the distribution of the formed Bi 2 O 3 phases. Red laser (633 nm) irradiation was found to induce the appearance of b-Bi 2 O 3 , within a certain range of power densities, by diffusion-controlled processes. In contrast, ultraviolet (UV, 325 nm) laser irradiation, above a certain power density threshold, initially induces the formation of both b and d-Bi 2 O 3 phases. The amount of the produced d-Bi 2 O 3 phase increases by increasing the irradiation time, while that of the b phase follows the opposite trend. UV laser irradiation seems to be a suitable method to produce room temperature stable d-Bi 2 O 3 patterns on Bi films.

Study of Annealing Temperature Effect on the Photovoltaic Performance of BiOI-Based Materials

“…The annealing treatment of BiOI at 550 • C can result in a different trend in its Raman spectra, as it can result in a change of BiOI chemical structure. We found the peak signals around 280-350 cm −1 and 445-485 cm −1 , which are close to the characteristic of β-Bi 2 O 3 [41]. By observing the XRD patterns and Raman spectra in Figures 1 and 2, we note that among the structure of BiOI and its derivations, Bi 5 O 7 I and Bi 2 O 3 are different from others.…”

Alternative Bi precursor effects on the structural, optical, morphological and photocatalytic properties of BiOI nanostructures

“…Regarding the peaks obtained around 130 and 310 cm −1 , they could be related with peaks reported around 118 and 310 cm −1 for samples of BiOI [27,37]. However, a more likely explanation for these peaks is that they appear due to the energy supplied locally by the laser irradiation during the Raman measurement, providing enough energy to induce changes in the crystalline phase [38]. There is a report showing that BiOI is sensible to thermal processes, losing I-atoms while gaining O-atoms simultaneously, as temperature increases until it is transformed to β-Bi 2 O 3 [30]; even at lower temperatures [39].…”

Femtosecond laser-induced periodic surface structures formation on bismuth thin films upon irradiation in ambient air

“…These spectra remain the same for both the non-irradiated and the irradiated analyzed spots on the sample. All the spectra show two characteristic peaks at 70 and 98 cm −1 , which correspond to the Raman bands, assigned to the Bi-Bi vibrations and the lattice vibration, respectively [10][11][12][13]. The change in the relative intensity between the bands indicates that the Bi LIPSS went through a change on its crystallographic orientation.…”

“…LIPSS formation on the surface of Bi can significantly change the physical properties of this material, leading to some new applications. Bi 2 O 3 has been generated in Bi with continuous wave (CW) or pulsed laser irradiation [10][11][12][13][14]. Also, the formation of LIPSS in Bi thin films by nanosecond pulsed laser irradiation was demonstrated in some prevoius work [8,9].…”