A novel approach for suppression of oxygen precipitation in CZ silicon wafers of solar cells by pre-thermal treatment

Abstract The aim of the paper was to apply the newly developed instruments ‘Corescan’ and ‘Sherescan’ in order to measure the essential parameters of producing solar cells in comparison with the standard techniques. The standard technique named the Transmission Line Method (TLM) is one way to monitor contacting process to measure contact resistance locally between the substrate and metallization. Nowadays, contact resistance is measured over the whole photovoltaic cell using Corescanner instrument. The Sherescan device in comparison with standard devices gives a possibility to measure the sheet resistance of the emitter of silicon wafers and determine of both P/N recognition and metal resistance. The Screen Printing (SP) method is the most widely used contact formation technique for commercial silicon solar cells. The contact resistance of manufactured front metallization depends of both the paste composition and co-firing conditions. Screen printed front side metallization and next to co-fired in the infrared conveyor furnace was carried out at various temperature from 770°C to 920°C. The silver paste used in the present paper is commercial. The investigations were carried out on monocrystalline silicon wafers. The topography of co-fired in the infrared belt furnace front metallization was investigated using the atomic force microscope and scanning electron microscope (SEM). There were researched also cross sections of front contacts using SEM microscope. Front contacts of the solar cells were formed on non-textured silicon surface with coated antireflection layer. On one hand, based on electrical properties investigations using Sherescan instrument it was obtained the knowledge of the emitter sheet resistance across the surface of a wafer, what is essential in optimizing the emitter diffusion process. On the other hand, it was found using Corescan instrument that the higher temperature apparently results in a strongly decreased contact resistance.

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Thermal pretreatment of diamond wire sawn multi-crystalline silicon wafers for wet acid texturization of solar cells

Materials Research Express ◽

10.1088/2053-1591/aaf118 ◽

2018 ◽

Vol 6 (2) ◽

pp. 025911

Author(s):

Jinbing Zhang ◽

Hongping Fu ◽

Xingfang Ye ◽

Lang Zhou

Keyword(s):

Solar Cells ◽

Crystalline Silicon ◽

Silicon Wafers ◽

Thermal Pretreatment ◽

Diamond Wire

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Pts-Oi Complex Formation in Platinum Diffused Silicon

MRS Proceedings ◽

10.1557/proc-864-e2.3 ◽

2005 ◽

Vol 864 ◽

Author(s):

Wilfried Vervisch ◽

Laurent Ventura ◽

Bernard Pichaud ◽

Gérard Ducreux ◽

André Lhorte

Keyword(s):

Thermal Treatment ◽

Complex Formation ◽

Cooling Rate ◽

Point Defects ◽

Diffusion Processes ◽

Silicon Wafers ◽

Doping Behaviour ◽

Simulation Results ◽

Dopant Atoms ◽

P Type

AbstractWhen platinum is diffused at temperatures higher than 900°C in Cz or FZ low doped n-type silicon samples, which are then cooled slowly in the range [1-10]°C/min, a p-type doping leading to the formation of a pn junction can be observed by spreading resistance measurement. The lower the cooling rate, the deeper the junction is. This junction disappears after a second thermal treatment finishing with a quenching step. A platinum related complex formation is considered to explain this reversible doping behaviour. Different possible interactions between platinum and other impurities such as dopant atoms, intrinsic point defects, and common residual impurities (C, Oi, transition metallic atoms) are studied here. Experimental results from Pt diffusion processes in different qualities of silicon wafers, and simulation results, lead to the conclusion that the platinum related p-type doping effect is due to the formation of a Pts-Oi complex.

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KOH-ETCH Related Defects on Processed Silicon Wafers

MRS Proceedings ◽

10.1557/proc-259-187 ◽

1992 ◽

Vol 259 ◽

Cited By ~ 1

Author(s):

Laurent E. Kassel

Keyword(s):

Thermal Treatment ◽

Epitaxial Growth ◽

Silicon Wafers ◽

Processing Steps ◽

Crystallographic Orientations

ABSTRACTKOH, an anisotropic etchant of monocrystalline Si, may cause roughness and defects whose shapes are related to crystallographic orientations. This paper studies the effect of processing steps on the formation of geometric etch defects. Implantation, thermal treatment, epitaxial growth or photoresist were not the source of such defects. In the scope of this study, only unwanted damage caused geometric etch defects. This makes the observation of the wafer after KOH etch a good indicator of the quality of previous steps.

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Проблемы при использовании травителя KOH-IPA для текстурирования кремниевых пластин

Журнал технической физики ◽

10.21883/jtf.2020.10.49810.431-19 ◽

2020 ◽

Vol 90 (10) ◽

pp. 1758

Author(s):

Н.А. Чучвага ◽

Н.М. Кислякова ◽

Н.С. Токмолдин ◽

Б.А. Ракыметов ◽

А.С. Серикканов

Keyword(s):

Solar Cells ◽

High Efficiency ◽

Main Type ◽

Single Crystal Silicon ◽

Silicon Wafers ◽

Optimal Parameters ◽

Crystal Silicon ◽

High Efficiency Solar Cells ◽

Wet Chemical ◽

Manufacturing Techniques

The wet chemical treatment of monocrystalline silicon wafers, said method comprising texturing, represents one of the fundamental steps of manufacturing techniques of high-efficiency solar cells. As part of this work, methods for texturing single-crystal silicon wafers for solar cells were studied.As a result of studies, the optimal parameters of texturing technology for the studied samples were determined. The main type of etchant for texturing processes, which is a solution of KOH with isopropanol, is also determined.

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