Influence of back contact morphology on light trapping and plasmonic effects in microcrystalline silicon single junction and micromorph tandem solar cells

Jovanov, Vladislav; Planchoke, Ujwol; Magnus, Philipp; Stiebig, Helmut; Knipp, Dietmar

doi:10.1016/j.solmat.2012.11.022

Cited by 38 publications

(41 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…On the other hand, Schmid et al [140] showed that the transition from a single nanoparticle to a density of particles already modifies the scattering performances predicted by Mie theory. The high absorption together with the weak wavelength dependence, as observed here between 800 and 1000 nm, thus could also be dominated by the parasitic losses in the metal as it has already been pointed out before [24,29,141,142].…”

Section: Absorption Measurementssupporting

confidence: 56%

Diffractive Optics for Thin-Film Silicon Solar Cells

Schuster¹

2017

Springer Theses

View full text Add to dashboard Cite

Thin-film silicon solar cells have the potential to convert sunlight into electricity at high efficiency, low cost and without generating pollutants. However, they need to become more competitive with conventional energy technologies by increasing their efficiency.One of the key efficiency limitations of using thin silicon absorber materials relates to the optical loss of low-energy photons, because the absorption coefficient of silicon decreases strongly for these low-energy photons in the red and nearinfrared, such that the absorption length becomes longer than the absorber layer thickness. If, in contrast, the incident light was redirected and trapped into the plane of the silicon slab, a thin-film could absorb as much light as a thick layer.Diffractive textures can not only efficiently scatter the low-energy photons, but are also able to suppress the reflection of the incident sunlight. In order to take advantage of the full benefits that textures can offer, I outline a simple layer transfer technique that allows the structuring of a thin-film independently from both sides, and use absorption measurements to show that structuring on both sides is favourable compared to structuring on one side only. I also introduce a figure-of-merit that can objectively and quantitatively assess the benefit of the structuring itself, which allows me to benchmark state-ofthe-art proposals and to deduce some important design rules. Minimising the parasitic losses, for example, is of critical importance, as the desired scattering properties are directly proportional to these losses. To study the impact of parasitics, I quantify the useful absorption enhancement of two different light trapping mechanisms, i.e. diffractive vs plasmonic, based on a fair and simple experimental comparison. The experiment demonstrates that diffractive light-trapping is a better choice for photovoltaic applications, because plasmonic structures accumulate the parasitical losses by multiple interactions with the trapped light.

show abstract

Section: Absorption Measurementssupporting

confidence: 56%

Diffractive Optics for Thin-Film Silicon Solar Cells

Schuster¹

2017

Springer Theses

View full text Add to dashboard Cite

show abstract

“…Furthermore a layer stack without back reflector is investigated in-situ. Here, light scattering at the in-coupling to silicon occurs at an interface between air and silicon which morphology is not only defined by the texture-etched TCO, but also by the growth of the silicon layer [12,13]. Light scattering properties are mainly defined by the interface morphology and the difference in refractive indices.…”

Section: -P3 Epj Photovoltaicsmentioning

confidence: 99%

“…Second, the texture of the silicon surface which is deposited on the textured ZnO:Al gradually changes with increasing the layer thickness of the silicon [12,13]. At the beginning, when only a very thin silicon layer is deposited, the ZnO:Al texture is present also on the silicon surface due to the conformity of the thin silicon on the rough ZnO:Al.…”

Section: -P3 Epj Photovoltaicsmentioning

confidence: 99%

In-situ determination of the effective absorbance of thinμc-Si:H layers growing on rough ZnO:Al

et al. 2013

View full text Add to dashboard Cite

In this study optical transmission measurements were performed in-situ during the growth of microcrystalline silicon (μc-Si:H) layers by plasma enhanced chemical vapor deposition (PECVD). The stable plasma emission was used as light source. The effective absorption coefficient of the thin μc-Si:H layers which were deposited on rough transparent conductive oxide (TCO) surfaces was calculated from the transient transmission signal. It was observed that by increasing the surface roughness of the TCO, the effective absorption coefficient increases which can be correlated to the increased light scattering effect and thus the enhanced light paths inside the silicon. A correlation between the in-situ determined effective absorbance of the μc-Si:H absorber layer and the short-circuit current density of μc-Si:H thin-film silicon solar cells was found. Hence, an attractive technique is demonstrated to study, on the one hand, the absorbance and the light trapping in thin films depending on the roughness of the substrate and, on the other hand, to estimate the short-circuit current density of thin-film solar cells in-situ, which makes the method interesting as a process control tool.

show abstract

“…They can increase the optical path length with strongly diffracting the light. [39][40][41][42][43][44][45][46] Biswas et al fabricated metallic photonic crystal back reflectors and deposit amorphous silicon (a-Si:H) on it. They observed a 7% increase in average light absorption in analogous with a flat reference device.…”

Section: Introductionmentioning

confidence: 99%

Plasmonic excitation-assisted optical and electric enhancement in ultra-thin solar cells: the influence of nano-strip cross section

2015

View full text Add to dashboard Cite

The effects of Ag nano-strips with triangle, rectangular and trapezoid cross sections on the optical absorption, generation rate, and short-circuit current density of ultra-thin solar cells were investigated. By putting the nano-strips as a grating structure on the top of the solar cells, the waveguide, surface plasmon polariton (SPP), and localized surface plasmon (LSP) modes, which are excited with the assistance of nano-strips, were evaluated in TE and TM polarizations. The results show, firstly, the TM modes are more influential than TE modes in optical and electrical properties enhancement of solar cell, because of plasmonic excitations in TM mode. Secondly, the trapezoid nano-strips reveal noticeable impact on the optical absorption, generation rate, and short-circuit current density enhancement than triangle and rectangular ones. In particular, the absorption of long wavelengths which is a challenge in ultra-thin solar cells is significantly improved by using Ag trapezoid nano-strips.

show abstract

Influence of back contact morphology on light trapping and plasmonic effects in microcrystalline silicon single junction and micromorph tandem solar cells

Cited by 38 publications

References 30 publications

Diffractive Optics for Thin-Film Silicon Solar Cells

Diffractive Optics for Thin-Film Silicon Solar Cells

In-situ determination of the effective absorbance of thinμc-Si:H layers growing on rough ZnO:Al

Plasmonic excitation-assisted optical and electric enhancement in ultra-thin solar cells: the influence of nano-strip cross section

Contact Info

Product

Resources

About