Analysis of nanosecond and femtosecond laser ablation of rear dielectrics of silicon wafer solar cells

Ali, Jaffar Moideen Yacob; Shanmugam, Vinodh; Khanna, Anuradha; Wang, Puqun; Balaji, Nagarajan; Tabajonda, Rowel Vigare; Perez, Delio Justiniani; Aberle, Armin G.; Mueller, Thomas

doi:10.1016/j.solmat.2018.12.002

Cited by 20 publications

(4 citation statements)

References 19 publications

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“…The observed decrease in bulk time in the phosphorous laser‐doped BSF sections is speculated to be due to two potential factors: laser‐induced bulk damage during the laser doping step and the formation of oxidation‐induced stacking faults in the subsequent wet thermal oxidation step. [ 19,33 ] Although the achieved cell efficiency is not particularly high, as the fabrication process was not optimized, it demonstrates the functionality of the novel patterning method to fabricate IBC solar cells.…”

Section: Resultsmentioning

confidence: 99%

“…However, laser ablation can cause unintentional laser‐induced damage such as surface melting, heat‐affected zones, microcracks, and point defects on the underlying silicon layer, negatively affecting solar cell performance. [ 19 ] Hence an additional wet bench step is introduced for laser‐induced damage removal before the subsequent high‐temperature step.…”

Section: Introductionmentioning

confidence: 99%

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Structuring Interdigitated Back Contact Solar Cells Using the Enhanced Oxidation Characteristics Under Laser‐Doped Back Surface Field Regions

Kuruganti,

Isabella,

Mihailetchi

2024

Physica Status Solidi (a)

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Interdigitated back contact (IBC) architecture can yield among the highest silicon wafer‐based solar cell conversion efficiencies. Since both polarities are realized on the rear side, there is a definite need for a patterning step. Some of the common patterning techniques involve photolithography, inkjet patterning, and laser ablation. This work introduces a novel patterning technique for structuring the rear side of IBC solar cells using the enhanced oxidation characteristics under the locally laser‐doped n++ back surface field (BSF) regions with high‐phosphorous surface concentrations. Phosphosilicate glass layers deposited via POCl3 diffusion serve as a precursor layer for the formation of local heavily laser‐doped n++ BSF regions. The laser‐doped n++ BSF regions exhibit a 2.6‐fold increase in oxide thickness compared to the nonlaser‐doped n+ BSF regions after undergoing high‐temperature wet thermal oxidation. The utilization of oxide thickness selectivity under laser‐doped and nonlaser‐doped regions serves two purposes in the context of the IBC solar cell, first patterning rear side and second acting as a masking layer for the subsequent boron diffusion. Proof‐of‐concept solar cells are fabricated using this novel patterning technique with a mean conversion efficiency of 20.41%.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Structuring Interdigitated Back Contact Solar Cells Using the Enhanced Oxidation Characteristics Under Laser‐Doped Back Surface Field Regions

Kuruganti,

Isabella,

Mihailetchi

2024

Physica Status Solidi (a)

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“…Besides, a large amount of material deposition at the crater's edge was observed in nanosecond laser processing. However, experimental studies of Ali et al 14 on laser ablation of SiN x layer of PERC solar cells reveal that the electrical performance of PERC solar cells fabricated using nanosecond laser processing is superior than femtosecond laser processing. The authors did a comparative study on the laser ablation of the passivation layer using nanosecond and femtosecond laser at green wavelengths.…”

Section: Introductionmentioning

confidence: 99%

An experimental study on laser ablation of Ultra-thin SiN_x layer of PERC solar cell

Rana

Khatri

Kottantharayil

et al. 2022

Journal of Micromanufacturing

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In this work, a nanosecond green laser (532 nm) is used to generate narrow openings by removing an ultra-thin (85 nm) SiN x layer that is coated on a silicon substrate for application in the fabrication of Passivated Emitter and Rear Contact (PERC) solar cells. An experimental analysis is presented to identify the optimal range of laser parameters for an efficient ablation with minimal damage to the silicon substrate. The ablated samples were characterized using a 3D profilometer to obtain the surface profiles and scanning electron microscope imaging to observe the surface quality. Further, energy-dispersive X-ray line analysis and atom probe tomography were performed to evaluate the nitrogen content on the surface and along the depth, respectively. The experimental results suggest that the SiN x layer starts to ablate only above a threshold laser fluence of 1.4 J/cm2, while the surface bulged out for laser fluence slightly below the ablation threshold. The central part of the ablated region was clean with a negligible nitrogen concentration at the surface, about ∼0.03% at a fluence of 2.4 J/cm2. Nitrogen concentration reduces continuously and almost becomes zero at 80 nm depth, suggesting complete ablation of the SiN x layer for establishing electrical contacts. The ablation width was close to the laser spot diameter only at lower values of the laser fluence. The lowest value of ablation depth was about 180 nm, suggesting that only about 95 nm layer of the silicon is ablated. The study demonstrates that nanosecond laser ablation is a potential technique for ablation of the SiN x layer of PERC solar cells but requires choosing the optimal parameters.

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“…The femtosecond laser patterned (FSLP) based PSCs showed the certified power conversion efficiency (PCE) of 8.22% under AM 1.5G illumination with 46.05% of average visible transmittance (AVT) which outperformed state-of-the-art ST-PSCs reported to date. There have been many studies that apply femtosecond lasers to solar cells (including siliconbased solar cells) for diverse modifications, [14][15][16][17][18][19][20] however there has been no approach to apply it to semitransparent perovskite solar cells for the purpose of layer etching. Acetone (∼99%, Samchun Chemical) and isopropanol (IPA; ∼99.5%, Samchun Chemical) were used as cleaning solvents for indium tin oxide (ITO) coated glasses (10 Ω sq −1 , AMG).…”

mentioning

confidence: 99%

Semitransparent perovskite solar cells with exceptional efficiency and transmittance

Lee¹,

Yoon²,

Lee³

et al. 2021

Appl. Phys. Express

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A general approach to developing semitransparent perovskite solar cells (ST-PSCs) is to use a transparent metal oxide to replace opaque metal electrodes. However, the performance of such solar cells, unlike that of those using evaporated metal electrodes, deteriorates due to insufficient conductivity of the metal oxide, etc. Herein, a femtosecond laser patterning method is proposed to achieve the efficiency and transparency of ST-PSCs with a typical metal electrode and facilitates the control of transmittance by varying the opening ratio. While providing average visible transmittance > 46%, a certified power conversion efficiency of 8.22% was attained, which outperformed state-of-the-art ST-PSCs reported to date.

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Analysis of nanosecond and femtosecond laser ablation of rear dielectrics of silicon wafer solar cells

Cited by 20 publications

References 19 publications

Structuring Interdigitated Back Contact Solar Cells Using the Enhanced Oxidation Characteristics Under Laser‐Doped Back Surface Field Regions

Structuring Interdigitated Back Contact Solar Cells Using the Enhanced Oxidation Characteristics Under Laser‐Doped Back Surface Field Regions

An experimental study on laser ablation of Ultra-thin SiN_x layer of PERC solar cell

Semitransparent perovskite solar cells with exceptional efficiency and transmittance

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Analysis of nanosecond and femtosecond laser ablation of rear dielectrics of silicon wafer solar cells

Cited by 20 publications

References 19 publications

Structuring Interdigitated Back Contact Solar Cells Using the Enhanced Oxidation Characteristics Under Laser‐Doped Back Surface Field Regions

Structuring Interdigitated Back Contact Solar Cells Using the Enhanced Oxidation Characteristics Under Laser‐Doped Back Surface Field Regions

An experimental study on laser ablation of Ultra-thin SiNx layer of PERC solar cell

Semitransparent perovskite solar cells with exceptional efficiency and transmittance

Contact Info

Product

Resources

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An experimental study on laser ablation of Ultra-thin SiN_x layer of PERC solar cell