Exploring hafnium oxide's potential for passivating contacts for silicon solar cells

Wratten, Ailish; Pain, Sophie L.; Yadav, Anjali; Khorani, Edris; Niewelt, Tim; Black, Lachlan E.; Bartholazzi, Gabriel; Walker, David; Grant, Nicholas E.; Murphy, John D.

doi:10.1016/j.solmat.2023.112457

Cited by 5 publications

(3 citation statements)

References 56 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Although there has been considerable interest in ALD-grown HfO x , there is a lack of consistency in film properties reported in the literature, as demonstrated in Table 1 of ref. 18. This is particularly evident when considering HfO x charge polarity, which has been reported as being both positive and negative, 8–14 even for films processed under very similar conditions.…”

Section: Introductionmentioning

confidence: 75%

“…1, the film is still amorphous, suggesting that crystallisation is not a pre-requisite for passivation, consistent with our prior work on ultra-thin hafnium oxide films. 18 Above this temperature, the passivation quality of O 3 –HfO x gradually degrades – this decline is likely due to degradation of the surface passivation rather than the bulk, as there is no evidence of degradation in samples of the same substrate type with the other two HfO x films. We have previously verified the stability of the substrate bulk carrier lifetime with O 2 –HfO x passivation of nominally identical substrates using a superacid-based re-passivation method.…”

Section: Resultsmentioning

confidence: 99%

“…8–14 ALD-grown HfO x passivation studies have achieved surface recombination velocities (SRVs) <10 cm s −1 (compared to <2 cm s −1 for thermal SiO 2 and <1 cm s −1 for ALD Al 2 O 3 ) 1,15,16 for films 10–20 nm thick. 8–14 In addition to its potential as an insulating silicon passivation layer, the electronic properties of HfO x make it a candidate for inclusion within passivating contact structures, either as a hole-selective contact 17,18 or as an interlayer. 19 Beyond silicon passivation, HfO x has been extensively researched by the (micro)electronics industry for applications in transistors and capacitors 20,21 due to its high dielectric constant, and as a protective barrier layer, due to the impressive chemical resistance of HfO x to etchants such as HF.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Influence of co-reactants on surface passivation by nanoscale hafnium oxide layers grown by atomic layer deposition on silicon

Pain,

Khorani,

Yadav

et al. 2024

RSC Appl. Interfaces

View full text Add to dashboard Cite

show abstract

Section: Introductionmentioning

confidence: 75%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Influence of co-reactants on surface passivation by nanoscale hafnium oxide layers grown by atomic layer deposition on silicon

Pain,

Khorani,

Yadav

et al. 2024

RSC Appl. Interfaces

View full text Add to dashboard Cite

show abstract

Triplet Exciton Sensitization of Silicon Mediated by Defect States in Hafnium Oxynitride

Nagaya,

Alexiu,

Perkinson

et al. 2024

Advanced Materials

View full text Add to dashboard Cite

Singlet exciton fission has the potential to increase the efficiency of crystalline silicon solar cells beyond the conventional single junction limit. Perhaps the largest obstacle to achieving this enhancement is uncertainty about energy coupling mechanisms at the interfaces between silicon and exciton fission materials such as tetracene. Here, the previously reported silicon‐hafnium oxynitride‐tetracene structure is studied and a combination of magnetic‐field‐dependent silicon photoluminescence measurements and density functional theory calculations is used to probe the influence of the interlayer composition on the triplet transfer process across the hafnium oxynitride interlayer. It is found that hafnium oxide interlayers do not show triplet exciton sensitization of silicon, and that nitrogen content in hafnium oxynitride layers is correlated with enhanced sensitization. Calculation results reveal that defects in hafnium oxynitride interlayers with higher nitrogen content introduce states close to the band‐edge of silicon, which can mediate the triplet exciton transfer process. Some defects introduce additional deleterious mid‐gap states, which may explain observed silicon photoluminescence quenching. These results show that band‐edge states can mediate the triplet exciton transfer process, potentially through a sequential charge transfer mechanism.

show abstract

Atomic Layer Deposition of Hafnium Oxide Passivating Layers on Silicon: Impact of Precursor Selection

Pain,

Yadav,

Walker

et al. 2024

Physica Rapid Research Ltrs

View full text Add to dashboard Cite

Hafnium oxide (HfOx) films grown by atomic layer deposition (ALD) have recently been demonstrated to provide high‐quality silicon surface passivation. Reports have suggested that changing the composition of the hafnium‐containing precursor can enable films of both charge polarities to be produced. Herein, the passivation quality of hafnium oxide grown with metal amide precursors and a tetrakis(ethylmethylamido)hafnium (TEMAHf) precursor is examined, considering film charge polarity, chemical‐ and field‐based passivation effects, and film crystallinity. Throughout, the properties of TEMAHf‐HfOx are benchmarked against that of hafnium oxide grown with a tetrakis(dimethylamido)hafnium precursor. It is found that precursor choice has no influence on the fixed negative charge polarity (of order −1012 q cm−2) of HfOx films grown via plasma‐enhanced ALD. TEMAHf‐HfOx passivation is influenced by post‐deposition annealing temperature and can passivate with a surface recombination velocity ≤3 cm s−1 on n‐type silicon, compared to surface recombination velocities ≤11 cm s−1 for TDMAHf‐HfOx of a similar thickness.

show abstract

Exploring hafnium oxide's potential for passivating contacts for silicon solar cells

Cited by 5 publications

References 56 publications

Influence of co-reactants on surface passivation by nanoscale hafnium oxide layers grown by atomic layer deposition on silicon

Influence of co-reactants on surface passivation by nanoscale hafnium oxide layers grown by atomic layer deposition on silicon

Triplet Exciton Sensitization of Silicon Mediated by Defect States in Hafnium Oxynitride

Atomic Layer Deposition of Hafnium Oxide Passivating Layers on Silicon: Impact of Precursor Selection

Contact Info

Product

Resources

About