Optical characterization of double-side-textured silicon wafer based on photonic nanostructures for thin-wafer crystalline silicon solar cells

Abstract

Crystalline silicon (c-Si) wafers have found extensive use in photovoltaic applications. In this regard, to enable advanced light manipulation in thinwafer c-Si solar cells, we demonstrate the fabrication of double-side-textured Si wafers composed of a front-surface photonic nanotexture fabricated with quantum dot arrays and a rear-surface microtexture. The addition of the rear-surface microtexture to a Si wafer with the frontsurface photonic nanotexture increases the wafer's optical absorption in the near-infrared region, thus enabling enhanced light trapping. Excitation spectroscopy reveals that the photoluminescence intensity in the Si wafer with the double-sided texture is higher than that in the Si wafer without the rear-surface microtexture, thus indicating an increase in true optical absorption in the Si wafer with the double-sided texture. Our results indicate that the double-sided textures, i.e., the front-surface photonic nanotexture and rear-surface microtexture, can effectively reduce the surface reflection loss and provide enhanced light trapping, respectively.

Impact of size distributions of Ge islands as etching masks for anisotropic etching on formation of anti-reflection structures

“…For this purpose, we have proposed the formation of the antireflection structures using Ge self-assembled islands grown by molecular beam epitaxy (MBE) as etching masks for Si alkaline wet etching with the etching margin of only ∼1 μm. [14][15][16][17][18][19] Moreover, the impact of Ge coverage on the morphology has been reported and the optical characteristics of the structures with optimized Ge amounts were shown to be comparable to those of the conventional pyramid texture. 19) However, many hollows on the top were found, which may cause surface recombination and have a negative influence on conversion efficiency.…”

Boron-doped p-BaSi2/n-Si solar cells formed on textured n-Si(0 0 1) with a pyramid structure consisting of {1 1 1} facets

“…The samples were prepared as follows: first, the (001) surface of a Czochralski n-Si(001) substrate (ρ = 15 Ωcm) was cleaned by acetone and methanol to eliminate organics followed by dipping in HF/HNO3 mixed acid. Then, the substrate was immersed into SUN-X 600 (Wako) at 75 ºC for 30 min to form a pyramid structure consisting of {111} facets [24], and cleaned by sulfuric acid at 120 ºC for 15 min. After thermal cleaning of the substrate, Ba was deposited at 500 °C to form a 5 nm-thick BaSi2 epitaxial template by reactive deposition epitaxy.…”