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Article
Publication date: 2 July 2018

Wojciech Filipowski, Kazimierz Drabczyk, Edyta Wróbel, Piotr Sobik, Krzysztof Waczynski and Natalia Waczynska-Niemiec

The purpose of this paper is to develop a method of preparing spray-on dopant solutions that enable obtaining a p+ region forming a back-surface field (BSF) during the diffusion…

Abstract

Purpose

The purpose of this paper is to develop a method of preparing spray-on dopant solutions that enable obtaining a p+ region forming a back-surface field (BSF) during the diffusion doping process. The spray-on method used allows to decrease the costs of dopant solution application, which is particularly significant for new low-cost production processes.

Design/methodology/approach

This paper presents steps of production of high concentration boron dopant solutions enabling diffusion doping of crystalline p-type silicon surfaces. To check the fabricated dopant solutions for stability and suitability for spray-on application, their viscosity and density were measured in week-long intervals. The dopant solutions described in this paper were used in a series of diffusion doping processes to confirm their suitability for BSF production.

Findings

A method of preparing dopant solutions with parameters enabling depositing them on silicon wafers by the spray-on method has been established. Due to hygroscopic properties of the researched dopant solutions, a maximum surrounding atmosphere humidity has been established. The solutions should not be applied by the spray-on method, if this humidity value is exceeded. The conducted derivatographic examination enabled establishing optimal drying conditions.

Originality/value

The paper presents a new composition of a dopant solution which contains high concentration of boron and may be applied by the spray-on method. Derivatographic examination results, as well as equations describing the relation between dopant solution density and viscosity and storage time are also original for this research. The established dependencies between the sheet resistance of the fabricated BSF and the diffusion doping time are other new elements described in the paper.

Details

Microelectronics International, vol. 35 no. 3
Type: Research Article
ISSN: 1356-5362

Keywords

Article
Publication date: 7 August 2017

Wojciech Filipowski, Edyta Wrobel, Kazimierz Drabczyk, Krzysztof Waczynski, Grazyna Kulesza-Matlak and Marek Lipinski

The main aim of this study was a preparation development of dopant solution (DS) which can be deposited by a spray-on method and subsequently allows obtaining the n+ emitter layer…

Abstract

Purpose

The main aim of this study was a preparation development of dopant solution (DS) which can be deposited by a spray-on method and subsequently allows obtaining the n+ emitter layer with surface resistance in the range of 65-80 Ω−1. The intention of chosen spray-on method was to gain a cheaper way of dopant source deposition, compared to the commonly used methods, which is of particular importance for the new low-cost production processes.

Design/methodology/approach

This paper presents the sequence in producing a spray-on glass solution (DS) with very high concentration of phosphorus, which allows to perform diffusion doping at relatively low temperatures. DS contained deionized water, ethyl alcohol, tetraethoxysilane and othophosphoric acid.

Findings

The sequence in producing a DS was performed with respect to enabling the application to silicon wafers by spray-on method. Furthermore, the equations defined density and viscosity of DS in term of storage time were referred to determine the possibility of applying this solution by spray-on method. Besides, the dependence of the emitter surface resistance on the doping (diffusion) time was determined. Accordingly, optimal process conditions were specified.

Originality/value

The paper presents a new, so far unpublished composition of DS with very high concentration of phosphorus, which can be applied using a spray-on method. Moreover, original are also investigations respecting some properties of obtained DS relative to storage time.

Details

Microelectronics International, vol. 34 no. 3
Type: Research Article
ISSN: 1356-5362

Keywords

Article
Publication date: 18 June 2019

Piotr Sobik, Radosław Pawłowski, Anna Pluta, Olgierd Jeremiasz, Kazimierz Drabczyk, Grażyna Kulesza-Matlak and Paweł Antoni Zięba

The purpose of this paper is to investigate the behavior of interconnections between solar cells in a glass-free solar modules. As glass weight can be a limitation, it is still…

Abstract

Purpose

The purpose of this paper is to investigate the behavior of interconnections between solar cells in a glass-free solar modules. As glass weight can be a limitation, it is still interesting to investigate other types of systems, especially when the glass was replaced with a polymeric front sheet. Such systems can be more sensitive for the solar cell interconnection ribbon fatigue.

Design/methodology/approach

To examine this effect, the set of glass-based and glass-free modules were prepared using various ribbon thickness and treatment concerning its stretching or curving before lamination. Furthermore, additional reinforcement of the connection between the ribbon and the solar cell was proposed. The prepared modules were exposed to the cyclic temperature variation in the environment chamber. The number of cycles after which the interconnection maintains its conductivity was noted.

Findings

Changing the outer layers into more elastic ones requires additional care for the ribbon treatment because interconnections become more sensitive for a system relative displacement. To secure interconnection before fatigue an additional curving of ribbon between solar cells can be introduced whereas the best results were obtained for a system with aluminum plate laminated as an interlayer.

Originality/value

The paper presents a new system of a glass-free solar module based on epoxy-glass fiber composite as a backsheet. The glass front sheet was replaced with an elastic, transparent polymer. Such construction can be used in a system where the glass weight is a limitation. As glass has a structural function in traditional modules and limits fatigues of interconnections the proposed system requires additional ribbon treatment to preserve long module life-span.

Details

Microelectronics International, vol. 36 no. 3
Type: Research Article
ISSN: 1356-5362

Keywords

Article
Publication date: 24 October 2022

Wojciech Filipowski

The purpose of this paper is to develop a model that allows determining the boron concentration profile in silicon based on duration and temperature of the diffusion process.

Abstract

Purpose

The purpose of this paper is to develop a model that allows determining the boron concentration profile in silicon based on duration and temperature of the diffusion process.

Design/methodology/approach

The model was developed on the basis of the Fick’s second law, which is fundamental for describing the diffusion process. The explicit scheme of the finite difference method was used in the conducted simulations. Results of measurements made using the secondary ion mass spectrometry (SIMS) were used as template dopant concentration profiles. Solution of boric acid in ethanol is the dopant source for which this model was developed.

Findings

Based on the conducted simulations, it was proposed that besides the influence of electric field of ionized dopants, which is already described in literature, an appropriate factor reflecting the influence of the threshold concentration on the coefficient of diffusion of boron in silicone should also be introduced.

Originality/value

The developed model enables determination of the boron concentration profile in silicon consistent with the results of SIMS measurements. A factor taking into account the influence of threshold concentration on the coefficient of diffusion was introduced. The influence of concentration of boric acid in the dopant solution on the concentration profile was also considered.

Details

Microelectronics International, vol. 40 no. 4
Type: Research Article
ISSN: 1356-5362

Keywords

Content available
Article
Publication date: 7 August 2017

Agata Skwarek

272

Abstract

Details

Microelectronics International, vol. 34 no. 3
Type: Research Article
ISSN: 1356-5362

Article
Publication date: 20 June 2019

Wojciech Filipowski

The purpose of this paper was the development of a model enabling precise determination of phosphorus concentration profile in the emitter layer of a silicon solar cell on the…

Abstract

Purpose

The purpose of this paper was the development of a model enabling precise determination of phosphorus concentration profile in the emitter layer of a silicon solar cell on the basis of diffusion doping process duration and temperature. Fick’s second law, which is fundamental for describing the diffusion process, was assumed as the basis for the model.

Design/methodology/approach

To establish a theoretical model of the process of phosphorus diffusion in silicon, real concentration profiles measured using the secondary ion mass spectrometry (SIMS) method were used. Samples with the phosphorus dopant source applied onto monocrystalline silicon surface were placed in the heat zone of the open quartz tube furnace, where the diffusion process took place in the temperature of 880°C-940°C. The measured real concentration profiles of these samples became template profiles for the model in development.

Findings

The model was developed based on phenomena described in the literature, such as the influence of the electric field of dopant ionized atoms and the influence of dopant atom concentration nearing the maximum concentration on the value of diffusion coefficient. It was proposed to divide the diffusion area into low and high dopant concentration region.

Originality/value

A model has been established which enabled obtaining a high level of consistency between the phosphorus concentration profile developed theoretically and the real profile measured using the SIMS method. A coefficient of diffusion of phosphorus in silicon dependent on dopant concentration was calculated. Additionally, a function describing the boundary between the low and high dopant concentration regions was determined.

Details

Microelectronics International, vol. 36 no. 3
Type: Research Article
ISSN: 1356-5362

Keywords

Article
Publication date: 30 September 2022

Amirul Syafiq, Vengadaesvaran Balakrishnan and Nasrudin Abd. Rahim

This paper aims to design the nano-titanium dioxide (TiO2) coating system which has superhydrophilic property, self-cleaning mechanism and antifog property as well as strong…

Abstract

Purpose

This paper aims to design the nano-titanium dioxide (TiO2) coating system which has superhydrophilic property, self-cleaning mechanism and antifog property as well as strong adhesion on glass substrate.

Design/methodology/approach

Two hydrophilic materials have been used such as TiO2 nanoparticles as fillers and hydrophilic copolymer, Pluronic F-127 by using simple sol–gel approach. The prepared solution was applied onto glass through dip- and spray-coating techniques and then left for drying at ambient temperature.

Findings

The nano-TiO2 superhydrophilic coating has achieved the water contact angle of 4.9° ± 0.5°. The superhydrophilic coating showed great self-cleaning effect against concentrated syrup and methylene blue where thin layer of water washes the dirt contaminants away. The nano-TiO2 coating exhibits great antifog performance that maintains high transparency of around 89% when the coated glass is placed above hot-fog vapor for 10 min. The fog droplets were condensed into water film which allowed the transmission of light through the glass. The strong adhesion of coated glass shows no total failure at scratch profile when impacted with scratch load of 500, 800 and 1,200 mN.

Research limitations/implications

Findings will be useful in the development of self-cleaning superhydrophilic coating that is applicable on building glass and photovoltaic panel.

Practical implications

The developed nano-TiO2 coating is developed by the combination of hydrophilic organic copolymer–inorganic TiO2 network to achieve great superhydrophilic property, optimum self-cleaning ability and supreme antifog performance.

Social implications

The findings will be useful for residents in building glass window where the application will reduce dust accumulation and keep the glass clean for longer period.

Originality/value

The synthesis of nano-TiO2 superhydrophilic coating which can be sprayed on large glass panel and cured at ambient temperature.

Article
Publication date: 20 June 2019

Barbara Swatowska, Piotr Panek, Dagmara Michoń and Aleksandra Drygała

The purpose of this study was the comparison and analysis of the electrical parameters of two kinds of silicon solar cells (mono- and multicrystalline) of different emitter…

Abstract

Purpose

The purpose of this study was the comparison and analysis of the electrical parameters of two kinds of silicon solar cells (mono- and multicrystalline) of different emitter resistance.

Design/methodology/approach

By controlling of diffusion parameters, silicon mono- (Cz-Si) and multicrystalline (mc-Si) solar cells with different emitter resistance values were produced – 22 and 48 Ω/□. On the basis of current-voltage measurements of cells and contact resistance mapping, the properties of final solar cells based on two different materials were compared. Additionally, the influence of temperature on PV cells efficiency and open circuit voltage (Uoc) were investigated. The PC1D simulation was useful to determine spectral dependence of external quantum efficiency of solar cells with different emitter resistance. The silicon solar cells of 25 cm2 area and 240 µm thickness were investigated.

Findings

Considering the all stages of cell technology, the best structure is silicon solar cell with sheet resistance (Rsheet) of 45-48 Ω/□. Producing of an emitter with this resistance allowed to obtain cells with a fill factor between 0.725 and 0.758, Uoc between 585 and 612 mV, short circuit current (Isc) between 724 and 820 mA.

Originality/value

Measurements and analysis confirmed that mono- and multicrystalline silicon solar cells with 48 Ω/□ emitter resistance have better parameters than cells with Rsheet of 22 Ω/□. The contact resistance is the highest for mc-Si with Rsheet of 48 Ω/□ and reaches the value 3.8 Ωcm.

Details

Microelectronics International, vol. 36 no. 3
Type: Research Article
ISSN: 1356-5362

Keywords

Article
Publication date: 1 June 1980

Since starting work at the age of 17 as a laboratory assistant for Pilkington's Glass, it had been Valerie Craine's ambition to run her own business. Even when she had her first…

Abstract

Since starting work at the age of 17 as a laboratory assistant for Pilkington's Glass, it had been Valerie Craine's ambition to run her own business. Even when she had her first child ten years later, she did not think of herself as a housewife in the long term. In spare moments and while the children were at school, Valerie worked on a project in which she had a strong interest. She and her husband Ken—full‐time technical manager—felt that there was a need for a protective coating material suitable for glass containers used in industry, laboratories and hospitals for storing acids and chemicals. They finally developed a technique for spraying glass with a tough transparent plastic material. Sprayed on to a glass container, it forms a coating which remains intact even if the glass shatters. An enthusiastic response to Valerie's informal market research convinced her that their amateur project could become a profit making concern. But Valerie lacked commercial expertise and was also unsure whether she could adjust to a full‐time commitment outside the family. The New Enterprise Programme which she attended in Manchester in June last year helped her to develop the necessary professional approach and reassured her that she could cope with running a home and a business. Towards the end of the course, Valerie and Ken were sufficiently confident to apply for a second mortgage on their house to finance the business. ‘Through the advice I received on the course, I was able to present professionally laid out cash flow forecasts which impressed our bank manager and tipped the balance in our favour’ said Valerie. Valerie and two family friends who have come in as her partners are now coating 1,000 glass containers a day, based in small factory premises on a new industrial estate in Bournemouth. They already employ six part time staff. They have now also established that the coating can be applied to a range of glass products including fluorescent lighting. Costs are already being covered and expansion in the very near future seems assured.

Details

Industrial and Commercial Training, vol. 12 no. 6
Type: Research Article
ISSN: 0019-7858

Article
Publication date: 26 September 2022

Amirul Syafiq, Nasrudin Abd. Rahim, Vengadaesvaran Balakrishnan and A.K. Pandey

This paper introduced the simple synthesis process of self-cleaning coating with fog-resistance property using hydrophobic polydimethylsiloxane (PDMS) polymer and nano-calcium…

Abstract

Purpose

This paper introduced the simple synthesis process of self-cleaning coating with fog-resistance property using hydrophobic polydimethylsiloxane (PDMS) polymer and nano-calcium carbonate (nano-CaCO3) and titanium dioxide (TiO2).

Design/methodology/approach

The synthesis method of PDMS/nano-CaCO3-TiO2 is based on sol-gel process. The crosslinking between PDMS and nanoparticles is driven by the covalent bond at temperature of 50°C. The 3-Aminopropyltriethoxysilane is used as binder for nanoparticles attachment in polymer matrix. Two fabrication methods are used, which are dip- and spray-coating methods.

Findings

The prepared coated glass fulfilled the requirement of standard self-cleaning and fog-resistance performance. For the self-cleaning test BS EN 1096-5:2016, the coated glasses exhibited the dust haze value around 20%–25% at tilt angle of 10°. For the antifog test, the coated glasses showed the fog haze value were below 2% and the gloss value were above 85%. The obtained results completely achieved the standard antifog value ASTM F659-06 protocol.

Research limitations/implications

Findings will provide an infrastructure support for the building glass to enhance building’s energy efficiency, cleaning performance and friendly environment.

Practical implications

This study proposed the simple synthesis method using hydrophobic polymer and nano-CaCO3 and nano-TiO2, which can achieve optimum self-cleaning property at low tilt angle and fog-resistance performance for building glass.

Social implications

The research findings have high potential for building company, cleaning building company and government sector. The proposed project capable to reduces the energy consumption about 20% per annum due to labor cost, time-consuming and safety during manual cleaning.

Originality/value

The novel method to develop self-cleaning coating with fog-resistance using simple synthesis process and fabrication method for building glass application.

1 – 10 of 158