Behaviour of Light Induced Defect Generation and Carrier Lifetime Degradation in Solar Grade Silicon

Light-induced defect generation seriously reduces the minority-carrier lifetime of crystalline silicon (c-Si) wafers which causes a decrease in solar cell efficiency. In this paper we investigate the impact of boron-oxygen complexes and iron impurities on the light induced minority-carrier lifetime degradation in c-Si, comparing electronic grade and upgraded metallurgical grade materials. For the later, the characteristic of the decay process is shown to be composed of a fast initial decay and a subsequent slow asymptotic decay. We conclude that the dissociation of iron-boron pairs must be taken into account to explain the light-induced lifetime reduction.

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Minority Carrier Lifetime Improvement of Multicrystalline Silicon Using Combined Saw Damage Gettering and Emitter Formation

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.242.126 ◽

2015 ◽

Vol 242 ◽

pp. 126-132 ◽

Cited By ~ 4

Author(s):

George Martins ◽

Ruy S. Bonilla ◽

Toby Burton ◽

P. MacDonald ◽

Peter R. Wilshaw

Keyword(s):

Carrier Lifetime ◽

Minority Carrier ◽

Crystalline Silicon ◽

Minority Carrier Lifetime ◽

High Concentration ◽

Production Methods ◽

Cell Efficiency ◽

Annealing Conditions ◽

Maximum Lifetime ◽

Current Production

In this work we use Saw Damage Gettering (SDG) in combination with emitter formation to improve the minority carrier lifetime of highly contaminated multi-crystalline silicon wafers. This process is applied to wafers from the bottom of ingots, commonly referred to as the “red zone”, which are currently discarded since their high concentration of impurities limits the efficiency of solar cells produced therefrom. SDG is a potentially simple technique designed to upgrade these wafers. In this technique, bulk impurities are dissolved via annealing. The wafers are then cooled which generates a super-saturation of impurities in solution. The system then relaxes through the formation of precipitates in the saw damaged region. SDG is shown to be enhanced when using a temperature dependent cooling rate which maximizes the flux of impurities to the saw damaged regions. In addition, these benefits were observed even after an additional gettering process occurring during an emitter formation procedure. The SDG annealing conditions required to achieve the maximum lifetime were altered by the introduction of the emitter formation process. The enhancement generated by the SDG process may be sufficient to enable red-zone wafers to be processed is the same manner as higher quality no-red zone wafer wafers without adversely affecting the resultant cell efficiency. Due to its simplicity, it is expected that SDG can easily be incorporated into current production methods.

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Investigation on the Impact of Metallic Surface Contaminations on Minority Carrier Lifetime of a-Si:H Passivated Crystalline Silicon

Energy Procedia ◽

10.1016/j.egypro.2011.06.138 ◽

2011 ◽

Vol 8 ◽

pp. 288-293 ◽

Cited By ~ 3

Author(s):

Florian Sevenig ◽

Lena Breitenstein ◽

Antje Oltersdorf ◽

Karin Zimmermann ◽

Martin Hermle

Keyword(s):

Carrier Lifetime ◽

Minority Carrier ◽

Crystalline Silicon ◽

Minority Carrier Lifetime ◽

Metallic Surface ◽

The Impact

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Correlation between solar cell efficiency and minority carrier lifetime for batch processed multicrystalline Si wafers

Materials Science in Semiconductor Processing ◽

10.1016/j.mssp.2011.02.020 ◽

2011 ◽

Vol 14 (3-4) ◽

pp. 223-228 ◽

Cited By ~ 19

Author(s):

R. Jayakrishnan ◽

Shreyans Gandhi ◽

Prakash Suratkar

Keyword(s):

Solar Cell ◽

Carrier Lifetime ◽

Minority Carrier ◽

Minority Carrier Lifetime ◽

Solar Cell Efficiency ◽

Cell Efficiency

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Combined Effects of Pyramid-Like Structures and Antireflection Coating on Si Solar Cell Efficiency

Journal of Nanoscience and Nanotechnology ◽

10.1166/jnn.2015.11204 ◽

2015 ◽

Vol 15 (10) ◽

pp. 7624-7631 ◽

Cited By ~ 1

Author(s):

Chanseob Cho ◽

Junghwa Oh ◽

Byeungleul Lee ◽

Bonghwan Kim

Keyword(s):

Solar Cell ◽

Thermal Annealing ◽

Carrier Lifetime ◽

Minority Carrier ◽

Minority Carrier Lifetime ◽

Antireflection Coating ◽

Si Substrate ◽

Solar Cell Efficiency ◽

Cell Efficiency ◽

Uniform Doping

We developed a novel process for synthesizing Si solar cells with improved efficiencies. The process involved the formation of pyramid-like structures on the Si substrate and the deposition and subsequent thermal annealing of an antireflection coating. The process consisted of three main stages. First, pyramid-like structures were textured on the Si substrate by reactive ion etching and subsequently etched using a mixture of HF, HNO3, and deionized water for 300 s. Next, an antireflection coating was deposited on the substrate and was subsequently thermally annealed in a furnace in a N2 atmosphere. After the annealing process, the minority carrier lifetime increased by approximately 40 μs. Further, because of the increase in the minority carrier lifetime and the uniform doping of the substrate, the leakage current decreased. As a result, the efficiency of resulting solar cell increased to 17.24%, in contrast to that of the reference cell, which was only 15.89%. Thus, uniform doping and the thermal annealing of the antireflective coating improved solar cell efficiency.

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High minority carrier lifetime in amorphous-crystalline silicon heterostructure using triode rf PECVD

2020 47th IEEE Photovoltaic Specialists Conference (PVSC) ◽

10.1109/pvsc45281.2020.9300444 ◽

2020 ◽

Author(s):

Pratish Mahtani ◽

Sara M. Almenabawy ◽

Rajiv Prinja ◽

Geetu Sharma ◽

Nazir P. Kherani

Keyword(s):

Carrier Lifetime ◽

Minority Carrier ◽

Crystalline Silicon ◽

Minority Carrier Lifetime

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Correlation of Fe-Rich Defect Centre and Minority Carrier Lifetime in p-Type Multicrystalline Silicon

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.440.82 ◽

2013 ◽

Vol 440 ◽

pp. 82-87 ◽

Cited By ~ 2

Author(s):

Mohammad Jahangir Alam ◽

Mohammad Ziaur Rahman

Keyword(s):

Carrier Lifetime ◽

Minority Carrier ◽

Minority Carrier Lifetime ◽

Multicrystalline Silicon ◽

Recombination Lifetime ◽

Spatially Resolved ◽

Carrier Recombination ◽

Negative Role ◽

P Type ◽

The Impact

A comparative study has been made to analyze the impact of interstitial iron in minority carrier lifetime of multicrystalline silicon (mc-Si). It is shown that iron plays a negative role and is considered very detrimental for minority carrier recombination lifetime. The analytical results of this study are aligned with the spatially resolved imaging analysis of iron rich mc-Si.

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