Nanosolar, Inc.

Other

Aeris Capital Sustainable IP Ltd.

Jeroen K J Van Duren

Matthew R Robinson

Brian M Sager

Chris Eberspacher

Craig Leidholm

Martin R Roscheisen

James R Sheats

Brent Bollman

Methods and devices are provided for high-throughput printing of semiconductor precursor layer from microflake particles. In one embodiment, the method comprises of transforming non-planar or planar precursor materials in an appropriate vehicle under the appropriate conditions to create dispersions of planar particles with stoichiometric ratios of elements equal to that of the feedstock or precursor materials, even after settling. In particular, planar particles disperse more easily, form much denser coatings (or form coatings with more interparticle contact area), and anneal into fused, dense films at a lower temperature and/or time than their counterparts made from spherical nanoparticles. These planar particles may be microflakes that have a high aspect ratio. The resulting dense film formed from microflakes are particularly useful in forming photovoltaic devices.

High-throughput printing of semiconductor precursor layer from microflake particles

Methods and devices are provided for transforming non-planar or planar precursor materials in an appropriate vehicle under the appropriate conditions to create dispersions of planar particles with stoichiometric ratios of elements equal to that of the feedstock or precursor materials, even after selective forces settling. In particular, planar particles disperse more easily, form much denser coatings (or form coatings with more interparticle contact area), and anneal into fused, dense films at a lower temperature and/or time than their counterparts made from spherical nanoparticles. These planar particles may be nanoflakes that have a high aspect ratio. The resulting dense films formed from nanoflakes are particularly useful in forming photovoltaic devices.

High-throughput printing of semiconductor precursor layer from nanoflake particles

Methods and devices are provided for high-throughput printing of semiconductor precursor layer from microflake particles. In one embodiment, the method comprises of transforming non-planar or planar precursor materials in an appropriate vehicle under the appropriate conditions to create dispersions of planar particles with stoichiometric ratios of elements equal to that of the feedstock or precursor materials, even after settling. In particular, planar particles disperse more easily, form much denser coatings (or form coatings with more interparticle contact area), and anneal into fused, dense films at a lower temperature and/or time than their counterparts made from spherical nanoparticles. These planar particles may be microflakes that have a high aspect ratio. The resulting dense film formed from microflakes is particularly useful in forming photovoltaic devices. In one embodiment, at least one set of the particles in the ink may be inter-metallic flake particles (microflake or nanoflake) containing at least one group IB-IIIA inter-metallic alloy phase.

High-throughput printing of semiconductor precursor layer from chalcogenide microflake particles

Methods and devices are provided for forming thin-films from solid group IIIA-based particles. In one embodiment, a method is provided for creating solid alloy particles. The method may include providing a first material containing at least one alloy comprising of: a) a group IIIA element, b) at least one group IB, IIIA, and/or VIA element different from the group IIIA element of a), and c) a group IA-based material. The group IA-based material may be included in an amount sufficient so that no liquid phase of the alloy is present in a temperature range between room temperature and a deposition temperature higher than room temperature, wherein the group IIIA element is otherwise liquid in that temperature range. The method may involve formulating a precursor material comprising of: a) particles of the first material and b) particles containing at least one element from one of the following: a group IB element, a group IIIA element, a group VIA element, alloys containing any of the foregoing elements, or combinations thereof.

Thin-film devices formed from solid group IIIA alloy particles

Methods and devices are provided for improved photovoltaic devices. Non-vacuum deposition of transparent conductive electrodes in a roll-to-roll manufacturing environment is disclosed. In one embodiment, a method is provided for forming a photovoltaic device. The method comprises processing a precursor layer in one or more steps to form a photovoltaic absorber layer; depositing a smoothing layer to fill gaps and depression in the absorber layer to reduce a roughness of the absorber layer; adding an insulating layer over the smooth layer; and forming a web-like layer of conductive material over the insulating layer. By way of nonlimiting example, the web-like layer of conductive material comprises a plurality of carbon nanotubes. In some embodiments, the absorber layer is a group IB-IIIA-VIA absorber layer.

Roll-to-roll non-vacuum deposition of transparent conductive electrodes

Methods and devices are provided for forming thin-films from solid group IIIA-based particles. In one embodiment of the present invention, a method is described comprising of providing a first material comprising an alloy of a) a group IIIA-based material and b) at least one other material. The material may be included in an amount sufficient so that no liquid phase of the alloy is present within the first material in a temperature range between room temperature and a deposition or pre-deposition temperature higher than room temperature, wherein the group IIIA-based material is otherwise liquid in that temperature range. The other material may be a group IA material. A precursor material may be formulated comprising a) particles of the first material and b) particles containing at least one element from the group consisting of: group IB, IIIA, VIA element, alloys containing any of the foregoing elements, or combinations thereof.

Thin-film devices formed from solid particles

Methods and devices are provided for forming thin-films from solid group IIIA-based particles. In one embodiment, a method is provided for bandgap grading in a thin-film device using such particles. The method may be comprised of providing a bandgap grading material comprising of an alloy having: a) a IIIA material and b) a group IA-based material, wherein the alloy has a higher melting temperature than a melting temperature of the IIIA material in elemental form. A precursor material may be deposited on a substrate to form a precursor layer. The precursor material comprising group IB, IIIA, and/or VIA based particles. The bandgap grading material of the alloy may be deposited after depositing the precursor material. The alloy in the grading material may react after the precursor layer has begun to sinter and thus maintains a higher concentration of IIIA material in a portion of the compound film that forms above a portion that sinters first.

Bandgap grading in thin-film devices via solid group IIIA particles

Methods and devices are provided for transforming non-planar or planar precursor materials in an appropriate vehicle under the appropriate conditions to create dispersions of planar particles with stoichiometric ratios of elements equal to that of the feedstock or precursor materials, even after selective forces settling. In particular, planar particles disperse more easily, form much denser coatings (or form coatings with more interparticle contact area), and anneal into fused, dense films at a lower temperature and/or time than their counterparts made from spherical nanoparticles. These planar particles may be nanoflakes that have a high aspect ratio. The resulting dense films formed from nanoflakes are particularly useful in forming photovoltaic devices. In one embodiment, at least one set of the particles in the ink may be inter-metallic flake particles (microflake or nanoflake) containing at least one group IB-IIIA inter-metallic alloy phase.

High-throughput printing of semiconductor precursor layer from chalcogenide nanoflake particles

A high-throughput method of forming a semiconductor precursor layer by use of a chalcogen-containing vapor is disclosed. In one embodiment, the method comprises forming a precursor material comprising group IB and/or group IIIA particles of any shape. The method may include forming a precursor layer of the precursor material over a surface of a substrate. The method may further include heating the particle precursor material in a substantially oxygen-free chalcogen atmosphere to a processing temperature sufficient to react the particles and to release chalcogen from the chalcogenide particles, wherein the chalcogen assumes a liquid form and acts as a flux to improve intermixing of elements to form a group IB-IIIA-chalcogenide film at a desired stoichiometric ratio. The chalcogen atmosphere may provide a partial pressure greater than or equal to the vapor pressure of liquid chalcogen in the precursor layer at the processing temperature.

High-throughput printing of semiconductor precursor layer by use of chalcogen-containing vapor and inter-metallic material

Methods and devices are provided for forming thin-films from solid group IIIA-based particles. In one embodiment of the present invention, a method is described comprising of providing a first material comprising an alloy of a) a group IIIA-based material and b) at least one other material. The material may be included in an amount sufficient so that no liquid phase of the alloy is present within the first material in a temperature range between room temperature and a deposition or pre-deposition temperature higher than room temperature, wherein the group IIIA-based material is otherwise liquid in that temperature range. The other material may be a group IA material. A precursor material may be formulated comprising a) particles of the first material and b) particles containing at least one element from the group consisting of: group IB, IIIA, VIA element, alloys containing any of the foregoing elements, or combinations thereof. The temperature range described above may be between about 20&#xb0; C. and about 200&#xb0; C. It should be understood that the alloy may have a higher melting temperature than a melting temperature of the IIIA-based material in elemental form.

A precursor material for forming a film of a group IB-IIIA-chalcogenide compound and a method of making this film are disclosed. The film contains group IB-chalcogenide nanoparticles and/or group IIIA-chalcogenide nanoparticles and/or nanoglobules and/or nanodroplets and a source of extra chalcogen. Alternatively, the film may contain core-shell nanoparticles having core nanoparticles include group IB and/or IIIA elements, which are coated with a shell of elemental chalcogen material. The method of making a film of group IB-IIIA-chalcogenide compound includes mixing the nanoparticles and/or nanoglobules and/or nanodroplets to form an ink, depositing the ink on a substrate, heating to melt the extra chalcogen and to react the chalcogen with the group IB and group IIIA elements and/or chalcogenides to form a dense film.

Growing community of inventors

San Francisco, CA, United States of America

Jeroen K J Van Duren