Impact of powder size on Spark Plasma Sintering of Indium Sulfide
(2023) KASM10 20231Centre for Analysis and Synthesis
- Abstract
- As society’s electricity demands increase, technical solutions and advancements are essential to meet energy needs. Solar energy is a promising source, and solar cells enable the conversion of sunlight into electricity. This study is in collaboration with Midsummer AB, a Swedish company that specializes in sustainable solar cells. The company employs a sputtering process for manufacturing these cells and aims to produce some of the sputtering targets in-house using spark plasma sintering (SPS) technology, which are utilized in the cell production. In particular, the study ́s aim is to investigate how sample sized indium sulfide (In2S3) targets can be produced by SPS, and how the grain size affects this process. The work consisted of four... (More)
- As society’s electricity demands increase, technical solutions and advancements are essential to meet energy needs. Solar energy is a promising source, and solar cells enable the conversion of sunlight into electricity. This study is in collaboration with Midsummer AB, a Swedish company that specializes in sustainable solar cells. The company employs a sputtering process for manufacturing these cells and aims to produce some of the sputtering targets in-house using spark plasma sintering (SPS) technology, which are utilized in the cell production. In particular, the study ́s aim is to investigate how sample sized indium sulfide (In2S3) targets can be produced by SPS, and how the grain size affects this process. The work consisted of four parts. Firstly, a literature study of the polymorphs of In2S3; β-In2S3, α-In2S3, and γ-In2S3, and their properties was performed. Secondly, In2S3 powder of three different grain sizes and former In2S3 targets used as references were characterized using techniques such as simultaneous thermal analysis (STA), X-ray diffraction (XRD), and scanning electron microscopy (SEM). This, with the purpose to investigate the effect of heating and cooling on the crystal structure, composition and microstucture of the different grain sized powders and to investigate the crystal structure of the reference targets. Thirdly, process parameters for the SPS were set by findings from literature and from the first analysis. Sample sized In2S3 targets were produced, using the three grain sizes, and important sputtering target properties such as density, resistivity and ocularity were evaluated. Lastly, selected targets were characterized with XRD and SEM, to investigate the crystal structure and microstructure. The findings of the study indicate that In2S3 exhibits different behavior when heated above the second phase transition compared to the first phase transition. However, regardless of the temperature used, the main phase observed in all the investigated compounds was identified as β-In2S3. In particular, the reference targets and produced sample targets with suitable, evaluated sputtering properties for the sputtering process were found to mainly exhibit β-In2S3. The study also identified two sets of process parameters, with temperatures of 600 °C and 700 °C, that achieved this outcome and produced intact targets for all the three grain sizes at this scale. At 850 °C, the targets did mainly contain β-In2S3, but were defective and more brittle. Interestingly, the study revealed that the grain size of the In2S3 samples has minimal impact on the final product from a processing perspective at this scale. This implies that different grain sizes can be used without significantly affecting the properties of the produced targets. The characterization techniques used in this thesis are found to be limited for final conclusions regarding the microstructure and crystal structure. In summary, this thesis contributes to the understanding of manufacturing In2S3 sample targets with proper sputtering properties. (Less)
- Popular Abstract
- Sustainable Solar Cell Material Production
As society’s electricity demands increase, technical solutions and advancements are essential to meet energy needs. Solar energy is a promising source, and solar cells enable the conversion of sunlight into electricity.
This study focuses on Midsummer AB, a Swedish company specializing in sustainable solar cells. The company aims to use indium sulfide sputtering targets, which are formed by heating and pressing indium sulfide powder into plates, for their solar cell manufacturing process. However, purchasing these targets is expensive and challenging. To address this, the study investigates the in-house production of indium sulfide targets by using their press that heats the powder sample... (More) - Sustainable Solar Cell Material Production
As society’s electricity demands increase, technical solutions and advancements are essential to meet energy needs. Solar energy is a promising source, and solar cells enable the conversion of sunlight into electricity.
This study focuses on Midsummer AB, a Swedish company specializing in sustainable solar cells. The company aims to use indium sulfide sputtering targets, which are formed by heating and pressing indium sulfide powder into plates, for their solar cell manufacturing process. However, purchasing these targets is expensive and challenging. To address this, the study investigates the in-house production of indium sulfide targets by using their press that heats the powder sample with a pulsed current, specifically called spark plasma sintering (SPS). The goal is to produce sample sized targets with properties suitable for the company’s solar cell manufacturing process.
To enable in-house production of indium sulfide plates for solar cell manufacturing, a fundamental study of the material was conducted. The study examined the effect of heat on the material and the impact of using three different sized powders of indium sulfide. Firstly, the powder was heated to different carefully selected temperatures, and then investigated in order to see if this had an impact on the structure of the material. It was revealed that the materials structure did not change significantly when exposed to different temperatures. Also, former indium sulfide targets used as references were investigated in order to get a clue of what structure is desired in the final product. Here, the reference targets were found to consist predominantly of one crystal structure. Secondly, indium sulfide sample targets were produced with SPS by using the three different sized powders. Parameters such as temperature and pressure were determined by findings from literature and from the first material analysis. Important properties of the sample targets such as density, resistivity and intactness were investigated. The temperature was the parameter that could be varied the most, and in turn also impacted the produced sample targets the most. All produced sample targets were found to have a suitable density and resistivity. Targets pressed at 600 °C and 700 °C were intact, while those at 850 °C were more brittle. Characterization techniques confirmed that all sample targets predominantly exhibited the same crystal structure as the reference targets. Notably, the size of the powders had minimal impact on the final product.
Meeting energy needs and finding sustainable technical solutions are crucial. This study offers valuable insights into the behavior of a specific material, indium sulfide, which has received limited investigation in this area. These findings are instrumental in optimizing the pressing process of indium sulfide powder for use in solar cell manufacturing. By understanding the key factors involved, the company can progress towards more sustainable products and advanced solar cell manufacturing techniques. Ultimately, this study has the potential to reduce the cost and increase accessibility of sustainably produced solar cells, making them more widely available. (Less)
Please use this url to cite or link to this publication:
http://lup.lub.lu.se/student-papers/record/9131015
- author
- Wilthorn, Caroline LU
- supervisor
- organization
- course
- KASM10 20231
- year
- 2023
- type
- H2 - Master's Degree (Two Years)
- subject
- keywords
- Indium sulfide, In2S3, Spark Plasma Sintering, Sputtering target, Grain size, Crystal structure, Microstructure, Materials chemistry
- language
- English
- id
- 9131015
- date added to LUP
- 2023-06-29 09:26:47
- date last changed
- 2023-06-29 09:26:47
@misc{9131015,
abstract = {{As society’s electricity demands increase, technical solutions and advancements are essential to meet energy needs. Solar energy is a promising source, and solar cells enable the conversion of sunlight into electricity. This study is in collaboration with Midsummer AB, a Swedish company that specializes in sustainable solar cells. The company employs a sputtering process for manufacturing these cells and aims to produce some of the sputtering targets in-house using spark plasma sintering (SPS) technology, which are utilized in the cell production. In particular, the study ́s aim is to investigate how sample sized indium sulfide (In2S3) targets can be produced by SPS, and how the grain size affects this process. The work consisted of four parts. Firstly, a literature study of the polymorphs of In2S3; β-In2S3, α-In2S3, and γ-In2S3, and their properties was performed. Secondly, In2S3 powder of three different grain sizes and former In2S3 targets used as references were characterized using techniques such as simultaneous thermal analysis (STA), X-ray diffraction (XRD), and scanning electron microscopy (SEM). This, with the purpose to investigate the effect of heating and cooling on the crystal structure, composition and microstucture of the different grain sized powders and to investigate the crystal structure of the reference targets. Thirdly, process parameters for the SPS were set by findings from literature and from the first analysis. Sample sized In2S3 targets were produced, using the three grain sizes, and important sputtering target properties such as density, resistivity and ocularity were evaluated. Lastly, selected targets were characterized with XRD and SEM, to investigate the crystal structure and microstructure. The findings of the study indicate that In2S3 exhibits different behavior when heated above the second phase transition compared to the first phase transition. However, regardless of the temperature used, the main phase observed in all the investigated compounds was identified as β-In2S3. In particular, the reference targets and produced sample targets with suitable, evaluated sputtering properties for the sputtering process were found to mainly exhibit β-In2S3. The study also identified two sets of process parameters, with temperatures of 600 °C and 700 °C, that achieved this outcome and produced intact targets for all the three grain sizes at this scale. At 850 °C, the targets did mainly contain β-In2S3, but were defective and more brittle. Interestingly, the study revealed that the grain size of the In2S3 samples has minimal impact on the final product from a processing perspective at this scale. This implies that different grain sizes can be used without significantly affecting the properties of the produced targets. The characterization techniques used in this thesis are found to be limited for final conclusions regarding the microstructure and crystal structure. In summary, this thesis contributes to the understanding of manufacturing In2S3 sample targets with proper sputtering properties.}},
author = {{Wilthorn, Caroline}},
language = {{eng}},
note = {{Student Paper}},
title = {{Impact of powder size on Spark Plasma Sintering of Indium Sulfide}},
year = {{2023}},
}