Efficient Broadband Light-Trapping Structures on Thin-Film Silicon Fabricated by Laser, Chemical and Hybrid Chemical/Laser Treatments

Abstract

Light-trapping structures formed on surfaces of various materials have attracted much attention in recent years due to their important role in many applications of science and technology. This article discusses various methods for manufacturing light-trapping “black” silicon, namely laser, chemical and hybrid chemical/laser ones. In addition to the widely explored laser texturing and chemical etching methods, we develop a hybrid chemical/laser texturing method, consisting in laser post-texturing of pyramidal structures obtained after chemical etching. After laser treatments the surface morphology was represented by a chaotic relief of microcones, while after chemical treatment it acquired a chaotic pyramidal relief. Moreover, laser texturing of preliminarily chemically microtextured silicon wafers is shown to take five-fold less time compared to bare flat silicon. In this case, the chemically/laser-treated samples exhibit average total reflectance in the spectral range of 250–1100 nm lower by 7–10% than after the purely chemical treatment.

Au-Hyperdoped Si Nanolayer: Laser Processing Techniques and Corresponding Material Properties

“…On the other hand, when using ns pulses, separate material clusters were formed on the surface (white spots in the SEM image). In addition, the resulting nanorelief on the surface in the case of ps-laser processing can be interpreted as light-trapping, which significantly reduces the reflection coefficient of the surface in the visible region of the spectrum [18]; however, within the framework of this article, this fact is not an advantage. EDX elemental maps of silicon and gold show that the ps-laser processing of the region (Figure 3f,g) provides a more uniform distribution of atoms of chemical elements on the surface compared to the ns-laser processing (Figure 3b,c), in which separate gold clusters were formed, taking into account the fact that the EDX study was carried out with the same parameters of the electron beam (accelerating voltage, cathode current, working distance, etc.)…”

“…On the other hand, when using ns pulses, separate material clusters were formed on the surface (white spots in the SEM image). In addition, the resulting nanorelief on the surface in the case of ps-laser processing can be interpreted as light-trapping, which significantly reduces the reflection coefficient of the surface in the visible region of the spectrum [ 18 ]; however, within the framework of this article, this fact is not an advantage.…”

Advances in Plasma and Laser Engineering

“…Maggiore et al,in [12], presented the use of two non-thermodynamic equilibrium surface treatment methods with ultrashort laser pulses to modify the surface of square plates made of austenitic stainless steel. Kovalev et al,in [13], discussed different methods for producing light-trapping "black" silicon, namely laser, chemical and hybrid chemical/laser. Wang et al,in [14], presented the results of a study where a steel plate was welded by ultrasonic-assisted narrow-gap laser welding with a filler wire, and the plasma was observed using a high-speed camera and spectrograph.…”

Polyethylene Protective Coating with Anti-Reflective Properties for Silicon Photovoltaic Cells

“…The modifications using various methods resulted in micro-and nanostructures that significantly reduced the reflectance of the silicon surface. Anti-reflective coatings for this type of cell could measurably enhance the light-trapping effect presented in [14]. The authors of refs.…”

“…The authors of paper [14] managed to produce light-trapping structures on a silicon surface by various processing methods-laser, chemical and hybrid chemical/laser texturing. The modifications using various methods resulted in micro-and nanostructures that significantly reduced the reflectance of the silicon surface.…”