| 1. |
- Chen, W. H., et al.
(författare)
-
Nanophotonics-based low-temperature PECVD epitaxial crystalline silicon solar cells
- 2016
-
Ingår i: Journal of Physics D: Applied Physics. - : IOP Publishing. - 1361-6463 .- 0022-3727. ; 49:12
-
Tidskriftsartikel (refereegranskat)abstract
- The enhancement of light absorption via nanopatterning in crystalline silicon solar cells is becoming extremely important with the decrease of wafer thickness for the further reduction of solar cell fabrication cost. In order to study the influence of nanopatterning on crystalline silicon thin-film solar cells, we applied two lithography techniques (laser interference lithography and nanoimprint lithography) combined with two etching techniques (dry and wet) to epitaxial crystalline silicon thin films deposited via plasma-enhanced chemical vapor deposition at 175 degrees C. The influence of nanopatterning with different etching profiles on solar cell performance is studied. We found that the etching profiles (pitch, depth and diameter) have a stronger impact on the passivation quality (open circuit voltage and fill factor) than on the optical performance (short circuit current density) of the solar cells. We also show that nanopatterns obtained via wet-etching can improve solar cell performance; and in contrast, dry-etching leads to poor passivation related to the etching profile, surface damage, and/ or contamination introduced during the etching process.
|
|
| 2. |
- Trompoukis, C., et al.
(författare)
-
Photonic nanostructures for advanced light trapping in thin crystalline silicon solar cells
- 2015
-
Ingår i: Physica Status Solidi (A) Applications and Materials Science. - : Wiley. - 1862-6319 .- 1862-6300. ; 212:1, s. 140-155
-
Tidskriftsartikel (refereegranskat)abstract
- We report on the fabrication, integration, and simulation, both optical and optoelectrical, of two-dimensional photonic nanostructures for advanced light trapping in thin crystalline silicon (c-Si) solar cells. The photonic nanostructures are fabricated by the combination of various lithography (nanoimprint, laser interference, and hole mask colloidal) and etching (dry plasma and wet chemical) techniques. The nanopatterning possibilities thus range from periodic to random corrugations and from inverted nanopyramids to high aspect ratio profiles. Optically, the nanopatterning results in better performance than the standard pyramid texturing, showing a more robust behavior with respect to light incidence angle. Electrically, wet etching results in higher minority carrier lifetimes compared to dry etching. From the integration of the photonic nanostructures into a micron-thin c-Si solar cell certain factors limiting the efficiencies are identified. More precisely: (a) the parasitic absorption is limiting the short circuit current, (b) the conformality of thin-film coatings on the nanopatterned surface is limiting the fill factor, and (c) the material damage from dry etching is limiting the open circuit voltage. From optical simulations, the optimal pattern parameters are identified. From optoelectrical simulations, cell design considerations are discussed, suggesting to position the junction on the opposite side of the nanopattern.
|
|
| 3. |
- Depauw, V., et al.
(författare)
-
Sunlight-thin nanophotonic monocrystalline silicon solar cells
- 2017
-
Ingår i: Nano Futures. - : IOP Publishing. - 2399-1984. ; 1:2
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Introducing nanophotonics into photovoltaics sets the path for scaling down the surface texture of crystalline-silicon solar cells from the micro-to the nanoscale, allowing to further boost the photon absorption while reducing silicon material loss. However, keeping excellent electrical performance has proven to be very challenging, as the absorber is damaged by the nanotexturing and the sensitivity to the surface recombination is dramatically increased. Here we realize a light-wavelength-scale nanotextured monocrystalline silicon cell with the confirmed efficiency of 8.6% and an effective thickness of only 830 nm. For this we adopt a self-assembled large-area and industry-compatible amorphous ordered nanopatterning, combined with an advanced surface passivation, earning strongly enhanced solar light absorption while retaining efficient electron collection. This prompts the development of highly efficient flexible and semitransparent photovoltaics, based on the industrially mature monocrystalline silicon technology.
|
|
| 4. |
- Jain, S., et al.
(författare)
-
Broadband absorption enhancement in ultra-thin crystalline Si solar cells by incorporating metallic and dielectric nanostructures in the back reflector
- 2015
-
Ingår i: Progress in Photovoltaics: Research and Applications. - : Wiley. - 1099-159X .- 1062-7995. ; 23:9, s. 1144-1156
-
Tidskriftsartikel (refereegranskat)abstract
- We propose a back reflecting scheme in order to enhance the maximum achievable current in one micron thick crystalline silicon solar cells. We perform 3D numerical investigations of the scattering properties of metallic nanostructures located at the back side and optimize them for enhancing absorption in the silicon layer. We validate our numerical results experimentally and also compare the absorption enhancement in the solar cell structure, both with quasi-periodic and random metallic nanostructures. We have looked at the interplay between the metallic nanostructures and an integrated back reflector. We show that the combination of metallic nanoparticles and a metallic reflector results in significant parasitic absorption. We compared this to another implementation based on titanium dioxide nanoparticles, which act as a Lambertian reflector of light. Our simulation and experimental results show that this proposed configuration results in reduced absorption losses and in broadband enhancement of absorption for ultra-thin solar cells, paving the way to an optimal back reflector for thin film photovoltaics.
|
|
| 5. |
- Jain, S., et al.
(författare)
-
Broadband absorption enhancement in ultra-thin crystalline silicon solar cells by incorporating low cost aluminum nanoparticles
- 2013
-
Ingår i: 39th IEEE Photovoltaic Specialists Conference. ; , s. 555-559
-
Konferensbidrag (refereegranskat)abstract
- In this study nanodisks made from aluminum are incorporated in a back-reflector scheme in order to enhance the maximum achievable current in one-micron thick crystalline silicon solar cells. We perform three-dimensional numerical investigations of the backward scattering properties of aluminum nanodisks located at the back side, and optimize them for enhancing the absorption in the silicon layer. We also compare our results with previously optimized silver nanodisks and show that Al nanodisks are nearly as efficient as Ag counterpart. We show that if the absorption in the metallic back reflector (flat metal layer) can be avoided; this results in a further enhancement in absorption in the ultra-thin silicon layer. The proposed configuration results in a broadband (500nm to 1200nm) enhancement of absorption (∼ 58 %) for ultra-thin solar cells and has a great potential in thin film photovoltaic.
|
|
| 6. |
- Trompoukis, C., et al.
(författare)
-
Disordered nanostructures by hole-mask colloidal lithography for advanced light trapping in silicon solar cells
- 2016
-
Ingår i: Optics Express. - : The Optical Society. - 1094-4087 .- 1094-4087. ; 24:2, s. A191-A201
-
Tidskriftsartikel (refereegranskat)abstract
- We report on the fabrication of disordered nanostructures by combining colloidal lithography and silicon etching. We show good control of the short-range ordered colloidal pattern for a wide range of bead sizes from 170 to 850 nm. The inter-particle spacing follows a Gaussian distribution with the average distance between two neighboring beads (center to center) being approximately twice their diameter, thus enabling the nanopatterning with dimensions relevant to the light wavelength scale. The disordered nanostructures result in a lower integrated reflectance (8.1%) than state-of-the-art random pyramid texturing (11.7%) when fabricated on 700 mu m thick wafers. When integrated in a 1.1 mu m thin crystalline silicon slab, the absorption is enhanced from 24.0% up to 64.3%. The broadening of resonant modes present for the disordered nanopattern offers a more broadband light confinement compared to a periodic nanopattern. Owing to its simplicity, versatility and the degrees of freedom it offers, this potentially low-cost bottom-up nanopatterning process opens perspectives towards the integration of advanced light-trapping schemes in thin solar cells.
|
|
