Microcrystalline bottom cells in large area thin film silicon MICROMORPH™ solar modules

Hoetzel, J.; Caglar, Onur; Cashmore, Julian S.; Goury, C.; Kalaš, J.; Klindworth, M.; Kupich, M.; Leu, G.-F.; Lindic, Marie-Hélène; Losio, Paolo A.; Mates, T.; Mereu, B.; Roschek, T.; Sinicco, I.

doi:10.1016/j.solmat.2016.05.043

Cited by 12 publications

(5 citation statements)

References 33 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Where along the growth position the cracks appear depends on the focal point of the features, which is a function of the feature size and depth. In Figure 10, about 3 μm of nc‐Si:H was grown on the different textures, which is representative for a nc‐Si:H absorber in a multijunction device, 40,41 and much thicker than the poly‐Si layer in a TOPcon device 42,43 and the required absorber thickness of a perovskites 44 or C(I)GS top cell 45 . The images show crack‐free, device quality nc‐Si:H growth on T2 that was smoothened for 300 seconds and T3 that was etched for 5 minutes.…”

Section: Resultsmentioning

confidence: 99%

Advanced textured monocrystalline silicon substrates with high optical scattering yields and low electrical recombination losses for supporting crack‐free nano‐ to poly‐crystalline film growth

Vrijer

Smets

2021

Energy Science & Engineering

View full text Add to dashboard Cite

Crystalline silicon tandem devices with perovskites, CIGS, and nanocrystalline silicon, as well as the TOPCon design, are incompatible with the conventional pyramidal surface texture of silicon. This is a result of crack formation in nano to polycrystalline growth on large sharp surface features. In this work, three texturing approaches are investigated, using alkaline and/or acidic wet chemical etches, that can lead to the crack‐free growth of nano to polycrystalline materials on textured surfaces. In this work, we show that without acidic smoothening, the fraction of <111> pyramidal surface coverage has to remain relatively small to prevent crack formation during crystalline growth on these surfaces. Applying an acidic etch as a function of time continuously smoothens surface features. This shifts the reflection to wider scattering angles and results in higher total reflected intensity with respect to the conventional texture, making it an interesting option for a wide variety of tandem pv applications. Finally, we demonstrate crater‐like features on a <100> monocrystalline silicon surface using an etching process including a sacrificial layer. These craters increase light scattering into wider angles, but to a lesser extent than the former approach. In terms of passivation, we demonstrate the positive effect of a post deposition hydrogen treatment. Initial dilution of the silane plasma improves passivation on a <111> surface, but is detrimental to passivation on a <100> surface, likely because the hydrogen dilution results in epitaxial growth at the c‐Si/a‐Si:H hetero‐interface. A minority carrier lifetime of over 3 ms has been achieved for all texturing approaches, after deposition of a 15 nm a‐Si:H layer on both sides of the wafer, for different a‐Si:H deposition and annealing schemes.

show abstract

Section: Resultsmentioning

confidence: 99%

Advanced textured monocrystalline silicon substrates with high optical scattering yields and low electrical recombination losses for supporting crack‐free nano‐ to poly‐crystalline film growth

Vrijer

Smets

2021

Energy Science & Engineering

View full text Add to dashboard Cite

show abstract

“…Variations in the degree of crystallinity in the μc-Si:H i-layer over the whole 1.43 m 2 area of the module that have been discussed by J. E. Hötzel et al [20] contributed to a distribution of conversion efficiency over the 13 371.1 cm 2 total active area such that there will have been some 1 cm 2 areas of the device with efficiencies greater than the average 13.2% value. Further differences between the published small area cell efficiencies and the large area module performance can perhaps be attributed to the additional light-soaking time used to stabilize the Table I).…”

Section: Record Module Performancementioning

confidence: 96%

“…It should be noted that in the case of performance measurements on small area cells, the use of an aperture mask can lead to small losses of current, or V OC and FF, depending on the precise geometry of the mask and the cell, whereas for the large area module reported here, performance may be also reduced because of small current or V OC losses at the laser scribe interconnections at each of the 196 segments. Variations in the degree of crystallinity in the μc-Si:H i-layer over the whole 1.43 m 2 area of the module that have been discussed by J. E. Hötzel et al [20] contributed to a distribution of conversion efficiency over the 13 371.1 cm 2 total active area such that there will have been some 1 cm 2 areas of the device with efficiencies greater than the average 13.2% value. Further differences between the published small area cell efficiencies and the large area module performance can perhaps be attributed to the additional light-soaking time used to stabilize the Table I).…”

Section: Record Module Performancementioning

confidence: 96%

Record 12.34% stabilized conversion efficiency in a large area thin‐film silicon tandem (MICROMORPH™) module

Cashmore¹,

Apolloni²,

Braga³

et al. 2015

Progress in Photovoltaics

View full text Add to dashboard Cite

Mass-adoption of thin-film silicon (TF-Si) photovoltaic modules as a renewable energy source can be viable if the cost of electricity production from the module is competitive with conventional energy solutions. Increased module performance (electrical power generated) is an approach to reduce this cost. Progress towards higher conversion efficiencies for 'champion' large area modules paves the way for mass-production module performance to follow. At TEL Solar AG, Trübbach, Switzerland, significant progress in the absolute stabilized module conversion efficiency has been achieved through optimized solar cell design that integrates high-quality amorphous and microcrystalline TF-Si-deposited materials with efficient light management and transparent conductive oxide layers in a tandem MICROMORPH ™ module. This letter reports a world record large area (1.43 m 2 ) stabilized module conversion efficiency of 12.34% certified by the European Solar Test Installation; an increase of more than 1.4% absolute compared with the previous record for a TF-Si triple junction large area module. This breakthrough result generates more than 13.2% stabilized efficiency from each equivalent 1 cm 2 of the active area of the full module.

show abstract

“…Microcrystalline silicon (µc-Si:H) has demonstrated to be an important material for the development and fabrication of large area semiconductor devices [1][2][3]. A widely used method to deposit these films is plasma enhanced chemical vapor deposition (PECVD) at low temperatures (200 • C) by employing a combination of SiH 4 and H 2 gas mixtures [4,5]. Currently, thin film solar cells and thin film transistors (TFTs) incorporate µc-Si:H films into their fabrication processes [6][7][8][9][10].…”

Section: Introductionmentioning

confidence: 99%

Comparative Study on the Quality of Microcrystalline and Epitaxial Silicon Films Produced by PECVD Using Identical SiF4 Based Process Conditions

et al. 2021

View full text Add to dashboard Cite

Hydrogenated microcrystalline silicon (µc-Si:H) and epitaxial silicon (epi-Si) films have been produced from SiF4, H2 and Ar mixtures by plasma enhanced chemical vapor deposition (PECVD) at 200 °C. Here, both films were produced using identical deposition conditions, to determine if the conditions for producing µc-Si with the largest crystalline fraction (XC), will also result in epi-Si films that encompass the best quality and largest crystalline silicon (c-Si) fraction. Both characteristics are of importance for the development of thin film transistors (TFTs), thin film solar cells and novel 3D devices since epi-Si films can be grown or etched in a selective manner. Therefore, we have distinguished that the H2/SiF4 ratio affects the XC of µc-Si, the c-Si fraction in epi-Si films, and the structure of the epi-Si/c-Si interface. Raman and UV-Vis ellipsometry were used to evaluate the crystalline volume fraction (Xc) and composition of the deposited layers, while the structure of the films were inspected by high resolution transmission electron microscopy (HRTEM). Notably, the conditions for producing µc-Si with the largest XC are different in comparison to the fabrication conditions of epi-Si films with the best quality and largest c-Si fraction.

show abstract

Microcrystalline bottom cells in large area thin film silicon MICROMORPH™ solar modules

Cited by 12 publications

References 33 publications

Advanced textured monocrystalline silicon substrates with high optical scattering yields and low electrical recombination losses for supporting crack‐free nano‐ to poly‐crystalline film growth

Advanced textured monocrystalline silicon substrates with high optical scattering yields and low electrical recombination losses for supporting crack‐free nano‐ to poly‐crystalline film growth

Record 12.34% stabilized conversion efficiency in a large area thin‐film silicon tandem (MICROMORPH™) module

Comparative Study on the Quality of Microcrystalline and Epitaxial Silicon Films Produced by PECVD Using Identical SiF4 Based Process Conditions

Contact Info

Product

Resources

About