Metallic Impurities in Mono and Multi-crystalline Silicon and Their Gettering by Phosphorus Diffusion

ABSTRACTWe report the results of a study of the microstructural changes brought about by the gettering of metallic impurities in silicon. Phosphorus gettering proceeds by the formation of metal disilicides at the silicon/phosphosilicate glass interface. By showing that iron is strongly localized at the interface by phosphorus gettering, we present the first evidence that phosphorus gettering can proceed independently of Fermi level effects. Our first results on the intrinsic gettering of nickel lend support to the notion that the emission of silicon interstitials brought about by phosphorus diffusion (and SiP formation), or intrinsic gettering (SiOx, formation), plays an important role in the gettering process.

Phosphorus Diffusion Gettering of Metallic Impurities in Silicon: Mechanisms beyond Segregation

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.95-96.527 ◽

2003 ◽

Vol 95-96 ◽

pp. 527-538 ◽

Cited By ~ 8

Author(s):

Wolfgang Schröter ◽

A. Döller ◽

A. Zozime ◽

Vitaly V. Kveder ◽

Michael Seibt ◽

...

Keyword(s):

Phosphorus Diffusion ◽

Metallic Impurities

Solid state diffusion of metallic impurities from crucible and coating materials into crystalline silicon ingots for PV application

Journal of Crystal Growth ◽

10.1016/j.jcrysgro.2020.125636 ◽

2020 ◽

Vol 540 ◽

pp. 125636

Author(s):

F. Sturm ◽

M. Trempa ◽

S. Schwanke ◽

K. Schuck ◽

C. Kranert ◽

...

Keyword(s):

Solid State ◽

Crystalline Silicon ◽

Solid State Diffusion ◽

Coating Materials ◽

State Diffusion ◽

Metallic Impurities

Simulated co-optimization of crystalline silicon solar cell throughput and efficiency using continuously ramping phosphorus diffusion profiles

2012 38th IEEE Photovoltaic Specialists Conference ◽

10.1109/pvsc.2012.6318036 ◽

2012 ◽

Cited By ~ 3

Author(s):

Ashley E. Morishige ◽

David P. Fenning ◽

Jasmin Hofstetter ◽

Douglas M. Powell ◽

Tonio Buonassisi

Keyword(s):

Solar Cell ◽

Silicon Solar Cell ◽

Crystalline Silicon ◽

Crystalline Silicon Solar Cell ◽

Phosphorus Diffusion ◽

Diffusion Profiles

External Gettering and Hydrogenation Effects on Electrical Properties of Multicrystalline Silicon Wafers

MRS Proceedings ◽

10.1557/proc-262-481 ◽

1992 ◽

Vol 262 ◽

Cited By ~ 2

Author(s):

I. Perichaud ◽

S. Martinuzzi

Keyword(s):

Electrical Properties ◽

Gas Flow ◽

Minority Carrier ◽

Silicon Wafers ◽

Multicrystalline Silicon ◽

Carrier Diffusion ◽

Phosphorus Diffusion ◽

Recombination Centers ◽

Metallic Impurities

ABSTRACTTo reduce the density of recombination centers, external gettering by phosphorus diffusion from a POCI3 source and hydrogénation were applied to 200 μm thick samples.Gettering was carried out at 850°C or 900°C, for 120 or 240 mn. Hydrogénations result of the annealing of samples at 400°C for 30 mn in gas flow. Thanks to arrays of mesa diodes, it is found that minority carrier diffusion lengths (Ln) are neatly improved by the gettering. The improvements are higher at 900°C than at 850°C, they increase with gettering time and SIMS analyses indicate that they are due to the removing of Fe, Cu and Ni atoms.Hydrogénation enhances Ln values in samples gettered at 850°C and the higher Ln the longer the gettering time. After hydrogénation, the values of Ln in the samples gettered at 850°C are comparable to those measured in samples gettered at 900°C. It is assumed that hydrogen is able to neutralize the activity of impurities which have not been gettered, like oxygen, and also that of residual metallic impurities.

Screen Printed Phosphorus Diffusion for Low-Cost and Simplified Industrial Mono-Crystalline Silicon Solar Cells

ECS Meeting Abstracts ◽

10.1149/ma2010-01/26/1317 ◽

2010 ◽

Keyword(s):

Solar Cells ◽

Crystalline Silicon ◽

Low Cost ◽

Silicon Solar Cells ◽

Phosphorus Diffusion ◽

Crystalline Silicon Solar Cells ◽

Screen Printed

Comparison of Efficiency and Kinetics of Phosphorus-Diffusion and Aluminum Gettering of Metal Impurities in Silicon: a Simulation study

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.156-158.229 ◽

2009 ◽

Vol 156-158 ◽

pp. 229-234 ◽

Cited By ~ 3

Author(s):

M.A. Falkenberg ◽

D. Abdelbarey ◽

Vitaly V. Kveder ◽

Michael Seibt

Keyword(s):

Crystalline Silicon ◽

Limiting Factor ◽

Dissolved Metals ◽

Metal Impurity ◽

Phosphorus Diffusion ◽

Metal Impurities ◽

Precipitate Dissolution ◽

Silicon Materials ◽

Further Development ◽

Kinetics Of

The efficiency of solar cells produced from crystalline silicon materials is considerably affected by the presence of metal impurities. In order to reduce the concentration of metal impurities, gettering processes as phosphorus diffusion gettering (PDG) and aluminum gettering (AlG) are routinely included in solar cell processing. Further development and optimization of gettering schemes has to ground on physics-based simulations of gettering processes. In this contribution we use quantitative simulations to compare the efficiency and kinetics of PDG and AlG in the presence of precipitates for interstitially dissolved metals, like iron, at different gettering conditions. Recently measured segregation coefficients of iron in liquid AlSi with respect to crystalline silicon are used in order to compare with PDG under typical conditions. It is shown that kinetics of both, PDG and AlG, can be separated into two regimes: (i) at low temperatures kinetics are limited by precipitate dissolution, and (ii) at high temperatures kinetics of AlG is mainly limited by metal impurity diffusion while phosphorus in-diffusion is the limiting factor of PDG.

Screen printed phosphorus diffusion for low-cost and simplified industrial mono-crystalline silicon solar cells

Solar Energy Materials and Solar Cells ◽

10.1016/j.solmat.2010.04.055 ◽

2011 ◽

Vol 95 (1) ◽

pp. 14-17 ◽

Cited By ~ 19

Author(s):

T.Y. Kwon ◽

D.H. Yang ◽

M.K. Ju ◽

W.W. Jung ◽

S.Y. Kim ◽

...

Keyword(s):

Solar Cells ◽

Crystalline Silicon ◽

Low Cost ◽

Silicon Solar Cells ◽

Phosphorus Diffusion ◽

Crystalline Silicon Solar Cells ◽

Screen Printed

Comparison of Efficiencies of Different Surface Passivations Applied to Crystalline Silicon

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.108-109.585 ◽

2005 ◽

Vol 108-109 ◽

pp. 585-590 ◽

Cited By ~ 2

Author(s):

Olivier Palais ◽

Mustapha Lemiti ◽

Jean-Francois Lelievre ◽

Santo Martinuzzi

Keyword(s):

Silicon Surface ◽

Surface Passivation ◽

Crystalline Silicon ◽

Surface Recombination ◽

Surface Recombination Velocity ◽

Phosphorus Diffusion ◽

Type Silicon ◽

Good Surface ◽

Recombination Velocity ◽

P Type

In this work the efficiencies of different surface passivation techniques are compared. This paper emphasizes on the passivation provided by SiNx:H layers that is commonly used in photovolaic industry as surface passivation and anti reflection layer. The method used to evaluate the surface recombination velocity is detailed and discussed. It is shown that light phosphorus diffusion at 850°C – 20 min provides good surface passivation of n-type silicon surface and noticeable passivation of p-type, that can be improved by SiNx:H Layer.