Evolution of grain structure and recombination active dislocations in extraordinary tall conventional and high performance multi-crystalline silicon ingots

Trempa, M.; Kupka, I.; Kranert, C.; Lehmann, Toni; Reimann, C.; Friеdrich, J.

doi:10.1016/j.jcrysgro.2016.11.030

Cited by 24 publications

(6 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…While the average grain size of the bottom wafers is small, the grain structure of the top wafers is similar to those observed in conventional mc-Si. This is consistent with previous studies by Trempa et al 20) and Lehmann et al 3) Wafers towards the ingot top contain a higher density of dislocation clusters and a lower density of GBs, while the opposite is observed on wafers towards the ingot bottom. Lan et al 5) and Stokkan et al 21) proposed that it is due to fact that the propagation of dislocation networks can be supressed by the increased presence of GBs, which act as alternative sites for stress release during ingot growth.…”

Section: Characterisation Of Crystal Defectssupporting

confidence: 93%

Recombination sources in p-type high performance multicrystalline silicon

Sio

Phang

Zheng³

et al. 2017

Jpn. J. Appl. Phys.

View full text Add to dashboard Cite

This paper presents a comprehensive assessment of the electronic properties of an industrially grown p-type high performance multicrystalline silicon ingot. Wafers from different positions of the ingot are analysed in terms of their material quality before and after phosphorus diffusion and hydrogenation, as well as their final cell performance. In addition to lifetime measurements, we apply a recently developed technique for imaging the recombination velocity of structural defects. Our results show that phosphorus gettering benefits the intra-grain regions but also activates the grain boundaries, resulting in a reduction in the average lifetimes. Hydrogenation can significantly improve the overall lifetimes, predominantly due to its ability to passivate grain boundaries. Dislocation clusters remain strongly recombination active after all processes. It is found that the final cell efficiency coincides with the varying material quality along the ingot. Wafers toward the ingot top are more influenced by carrier recombination at dislocation clusters, whereas wafers near the bottom are more affected by a combination of their lower intra-grain lifetimes and a greater density of recombination active grain boundaries.

show abstract

Section: Characterisation Of Crystal Defectssupporting

confidence: 93%

Recombination sources in p-type high performance multicrystalline silicon

Sio

Phang

Zheng³

et al. 2017

Jpn. J. Appl. Phys.

View full text Add to dashboard Cite

show abstract

“…Trempa et al [28] investigated the evolution of the material parameters of conventional vs. HPMC-Si, simulating a crystallization process whereby a tall ingot of 700 mm height was grown by sequentially using the top of a regularly sized ingot as the seed for growing another regularly sized ingot. They showed that the grain boundary distribution would stabilize at a common level regardless of starting conditions above 250 mm.…”

Section: Relationship Between Grain Boundaries and Dislocationsmentioning

confidence: 99%

Investigation of the Grain Boundary Character and Dislocation Density of Different Types of High Performance Multicrystalline Silicon

Stokkan

Song²,

Ryningen

2018

Crystals

View full text Add to dashboard Cite

Wafers from three heights and two different lateral positions (corner and centre) of four industrial multicrystalline silicon ingots were analysed with respect to their grain structure and dislocation density. Three of the ingots were non-seeded and one ingot was seeded. It was found that there is a strong correlation between the ratio of the densities of (coincidence site lattice) CSL grain boundaries and high angle grain boundaries in the bottom of a block and the dislocation cluster density higher in the block. In general, the seeded blocks, both the corner and centre block, have a lower dislocation cluster density than in the non-seeded blocks, which displayed a large variation. The density of the random angle boundaries in the corner blocks of the non-seeded ingots was similar to the density in the seeded ingots, while the density in the centre blocks was lower. However, the density of CSL boundaries was higher in all the non-seeded than in the seeded ingots. It appears that both of these grain boundary densities influence the presence of dislocation clusters, and we propose they act as dislocation sinks and sources, respectively. The ability to generate small grain size material without seeding appears to be correlated to the morphology of the coating, which is generally rougher in the corner positions than in the middle. Furthermore, the density of twins and CSL boundaries depends on the growth mode during initial growth and thus on the degree of supercooling. Controlling both these properties is important in order to be able to successfully produce uniform quality high-performance multicrystalline silicon by the advantageous non-seeding method.

show abstract

“…Several works can be found in the literature dealing with the formation and evolution of dislocation clusters in directionally so-lidified silicon crystals, investigating the cooled down ingot [3][4][5][6][7][8] . Ryningen et al [9] studied horizontal slices taken along the height of an ingot and suggested a mechanism where: i) dislocations are generated locally at sources e.g.…”

Section: Introductionmentioning

confidence: 99%

Dynamic observation of dislocation evolution and interaction with twin boundaries in silicon crystal growth using in – situ synchrotron X-ray diffraction imaging

et al. 2021

View full text Add to dashboard Cite

The grown-in dislocation dynamics and interaction mechanisms with growth twins are investigated in-situ during the directional solidification of silicon crystal. The melting, solidification and cooling down process is performed in a dedicated installation at the European synchrotron radiation facility and is fol-lowed by X-ray Bragg diffraction imaging techniques (X-ray topography) at the mesoscale in real-time. Existing dislocations in the seed are observed to propagate in the up-grown crystal via replicas. They ex-pand vertically with the moving solid-liquid interface being always aligned perpendicular to the growth front. During the solidification process when they meet a growth twin lamella ( 3{111}), they neither pile-up nor transmit through the boundary. They are blocked by the twin, but they continue to move laterally behind the growth front due to the thermomechanical stresses in the system. The existence of dis-locations at the solidliquid interface, their evolution and interaction with twin boundaries is discussed, as growth proceeds, based on a detailed crystallographic analysis of the system.

show abstract

Evolution of grain structure and recombination active dislocations in extraordinary tall conventional and high performance multi-crystalline silicon ingots

Cited by 24 publications

References 22 publications

Recombination sources in p-type high performance multicrystalline silicon

Recombination sources in p-type high performance multicrystalline silicon

Investigation of the Grain Boundary Character and Dislocation Density of Different Types of High Performance Multicrystalline Silicon

Dynamic observation of dislocation evolution and interaction with twin boundaries in silicon crystal growth using in – situ synchrotron X-ray diffraction imaging

Contact Info

Product

Resources

About