Studies on Femtosecond Laser Textured Broadband Anti-reflective Hierarchical a-SiNx:H Thin Films for Photovoltaic Applications

Abstract

Simple ultrafast laser writing for the fabrication of hierarchical silicon nitride (a-SiNx:H) microstructures is demonstrated as an effective antireflection coating. A wide range of Si-rich to N-rich a-SiNx:H thin films, having varied optical band gap (2.32–5.94 eV) and refractive index (2.8–1.7) of wavelength-ordered (∼λ/4) thickness, are deposited using the plasma-enhanced chemical vapor deposition technique. The high-intensity femtosecond laser (800 nm, 120 fs, 1 kHz) interaction with a-SiNx:H films resulted in diverse nano-/microstructures with systematic width and depth born out of nonlinear light–matter interactions. These experimentally demonstrated the extremely disordered micro–nano structures over a large area of ∼ 1 cm2 that exhibit significant light trapping and absorption capabilities over a broad spectral region of 200–1000 nm. The extensive reduction of reflection losses from 30 to 2.8% from pre- to post-laser texturing is a favorable condition for broadband anti-reflective coatings for enhanced light harvesting from prefabricated photovoltaic devices.

Photonic Band Gap and Fractal Resonances in Aperiodic Cantor-like Self-Similar a:SiNx Photonic Structures

“…The TMMsimulated reflection spectra by varying the refractive index contrast of constituent layers are plotted, and it is observed The respective optical band gaps are ∼5.9 eV (band edge at ∼210 nm) and 2.64 eV (band edge ∼470 nm). 42 The cross-sectional view of fabricated ACPQ (N=2) based DBR and aperiodic microcavities are shown in Figure 2. Further, to demonstrate the fabrication capability of aperiodic structures of orders N = 1 to 5 is realized from electrochemically induced porous silicon, and details can be found in Supporting Figure S6.…”

“…Based on the mentioned TMM simulations, the ACPQ of cantor tri-adic ( N = 2) structure was experimentally realized from PECVD deposition from nonstoichiometric silicon nitride (a:SiN x ) multilayers with stoichiometric ratios R = [N]/[Si] ∼ 1.54 (nitrogen-rich) and 0.36 (silicon-rich) for low and high refractive index layers ( n L = 1.8 and n H = 2.7), respectively. The respective optical band gaps are ∼5.9 eV (band edge at ∼210 nm) and 2.64 eV (band edge ∼470 nm) . The cross-sectional view of fabricated ACPQ (N=2) based DBR and aperiodic microcavities are shown in Figure .…”

Tuning LSPR of Thermal Spike-Induced Shape-Engineered Au Nanoparticles Embedded in Si3N4 Thin-Film Matrix for SERS Applications

“…A null ellipsometry study of optical constants of the as-deposited (bottom) Si 3 N 4 film indicates that the refractive index, thickness, and stoichiometry, ([N]/[Si]) are 1.9, ca. 85–90 nm, and 1.33, respectively . Additionally, the presence of Au traces inside the fabricated structure has been established by analyzing the proportion of atomic weights of metal elements in the untreated and post-treated samples with EDX (images not provided).…”

“…85−90 nm, and 1.33, respectively. 56 Additionally, the presence of Au traces inside the fabricated structure has been established by analyzing the proportion of atomic weights of metal elements in the untreated and post-treated samples with EDX (images not provided). The UV−visible reflection spectra at wavelengths between 350 and 850 nm of annealed Au NPs stacked between Si 3 N 4 thin layers, before and after SHI irradiation at different fluences, are shown in Figure 2a.…”

Low-carbon economic scheduling of photovoltaic energy storage charging and discharging integrated system considering photovoltaic consumption demand

“…Due to the particularity of the power system [5], electric energy will bring environmental problems while being produced [6], and the introduction of environmental factors poses new challenges to economic dispatch. Therefore [7], in the process of power system operation, it is necessary to consider both energy issues and environmental issues, and effectively ensure environmental quality while meeting economic dispatch [8]. How to improve the convergence speed and operation efficiency of the algorithm [9], and obtain better dispatching optimization results is the starting point for the innovation and improvement of the dynamic environmental economic dispatching problem of power system [10].…”