Imec

Interuniversitair Micro-elektronica Centrum Vzw

Photovoltech

Christophe Allebé

Jozef Szlufcik

Emmanuel Van Kerschaver

Guy Beaucarne

Frederic Dross

Frédéric Dross

A photovoltaic device is disclosed. In one aspect, the device is formed in a semiconductor substrate. It has a radiation receiving front surface and a rear surface. The device may have a first region of one conductivity type, a second region with the opposite conductivity type adjacent to the front surface, and an antireflection layer. The rear surface is covered by a dielectric layer covering also an inside surface of the via. The front surface has current collecting conductive contacts. The rear surface has conductive contacts extending through the dielectric. A conductive path is in the via for photogenerated current from the front surface. By having the dielectric all over, no aligning and masking is needed. The same dielectric serves to insulate, provide thermal protection, and helps in surface and bulk passivation. It also avoids the need for a junction region near the via, hence reducing unwanted recombination currents.

Photovoltaic cells having metal wrap through and improved passivation

A method of etching a semiconductor substrate is described, the method comprising the steps of applying a paste containing an etchant to the substrate, and carrying out a thermal processing step to etch a part or a layer of the substrate where the paste has been applied. The etchant paste is preferably a caustic etching paste. The etchant paste may be applied selectively to a major surface of the substrate to form a pattern of applied paste. For example, the paste may be applied by a printing method, such as screen-printing. The method may be used to produce solar cells.

Semiconductor etching paste and the use thereof for localized etching of semiconductor substrates

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Orbais, Belgium

Christophe Allebé