With a global market share of about 90%, crystalline silicon is by far the most important photovoltaic technology today. This article reviews the dynamic field of crystalline silicon photovoltaics from a device-engineering perspective. First, it discusses key factors responsible for the success of the classic dopant-diffused silicon homojunction solar cell. Next it analyzes two archetypal high-efficiency device architectures – the interdigitated back-contact silicon cell and the silicon heterojunction cell – both of which have demonstrated power conversion efficiencies greater than 25%. Last, it gives an up-to-date summary of promising recent pathways for further efficiency improvements and cost reduction employing novel carrier-selective passivating contact schemes, as well as tandem multi-junction architectures, in particular those that combine silicon absorbers with organic–inorganic perovskite materials.

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High-efficiency crystalline silicon solar cells: status and perspectives

Wire sawing technology has been widely adopted for slicing of brittle-and-hard materials including crystalline silicon, SiC and sapphire. This paper presents a literature review on the research efforts on wire sawing related topics. First, the system and process level investigations of wire sawing technology, including both multi-wire slurry sawing and diamond wire sawing, are summarized. Ingot materials used in wire sawing technology, as well as their properties and behavior during sawing operation are discussed. As modeling and analysis of single grit indentation and scribing of brittle materials provide fundamental insight on material removal and these can be leveraged for wire sawing analysis at system level, a review of those models and modified models proposed particularly for wire sawing process are also presented. After the survey of current state-of-the-art, this contribution proposes important research aspects to be further worked on to gain more complete scientific understanding of wire sawing technology.

Wire sawing technology: A state-of-the-art review

Next-generation multi-crystalline silicon solar cells: Diamond-wire sawing, nano-texture and high efficiency

Thin Czochralski silicon solar cells based on diamond wire sawing technology

For slicing crystalline silicon ingots, we have developed a novel fixed-abrasive wire where diamond grit is fixed onto a bare wire by resin bonding. The properties of the wafers sliced using a multi-wire saw with the fixed-abrasive wire have been investigated. When compared with the wafers sliced with the loose-abrasive wire, the slicing speed is improved by approximately 2.5-fold and the thicknesses of saw-damage layers are reduced by more than a factor of two. Polycrystalline silicon solar cells have been fabricated for the first time utilizing the wafers sliced with the fixed-abrasive wire, and the cells with the saw-damage etching depth of 7 µm have shown photovoltaic properties comparable to those prepared using the wafers sliced with the loose-abrasive wire and subsequently etched to remove the damage layers up to 15 µm. It has been clarified that wafer slicing using the fixed-abrasive wire is promising as a next-generation slicing technique for fabrication of solar cells, particularly thin silicon cells where the wafer thicknesses approach or become less than 150 µm. Copyright © 2010 John Wiley & Sons, Ltd.

N. Watanabe

Papers

Characterization of polycrystalline silicon wafers for solar cells sliced with novel fixed-abrasive wire

Characterization of Multicrystalline Silicon Wafers for Solar Cell Applications Sliced With a Fixed Abrasive Wire