SunPower Patent Grants

Solar cells with silicon nanoparticles that are coated with nanoparticle passivation film

Granted: September 22, 2015
Patent Number: 9142696
A laser contact process is employed to form contact holes to emitters of a solar cell. Doped silicon nanoparticles are formed over a substrate of the solar cell. The surface of individual or clusters of silicon nanoparticles is coated with a nanoparticle passivation film. Contact holes to emitters of the solar cell are formed by impinging a laser beam on the passivated silicon nanoparticles. For example, the laser contact process may be a laser ablation process. In that case, the…

Multi-path converters for PV substrings

Granted: September 15, 2015
Patent Number: 9136710
A method for converting power from a photovoltaic (PV) panel having substrings of PV cells, the method includes converting power from a first substring of the PV panel to generate a first DC output having a fixed portion and a variable portion, converting power from a second substring of the PV panel to generate a second DC output having a fixed portion and a variable portion, and combining the first and second DC outputs to generate a combined DC output. A power converter may include an…

Chucks for supporting solar cell in hot spot testing

Granted: August 25, 2015
Patent Number: 9116202
In an embodiment, a chuck to support a solar cell in hot spot testing is provided. This embodiment of the chuck comprises a base portion and a support portion disposed above the base portion. The support portion is configured to support the solar cell above the base portion and to define a cavity between a bottom surface of the solar cell and the base portion that thermally separates a portion of the bottom surface of the solar cell from the base portion.

Alignment for metallization

Granted: August 18, 2015
Patent Number: 9112097
Forming a metal layer on a solar cell. Forming a metal layer can include placing a patterned metal foil on the solar cell, where the patterned metal foil includes a positive busbar, a negative busbar, a positive contact finger extending from the positive busbar, a negative contact finger extending from the negative busbar, a metal strip, and one or more tabs. The positive and negative busbars and the positive and negative contact fingers can be connected to one another by the metal strip…

Method of fabricating a solar cell with a tunnel dielectric layer

Granted: August 18, 2015
Patent Number: 9112066
Method of fabricating solar cells with tunnel dielectric layers are described. Solar cells with tunnel dielectric layers are also described.

Junction box thermal management

Granted: August 4, 2015
Patent Number: 9101082
An electrical assembly may include an enclosure having a base portion to attach the enclosure to a panel and a heat dissipating portion opposite the base portion, a circuit board having a first thermal interface on a first side of the board, a second thermal interface on a second side of the board, and a thermally conductive portion to provide enhanced thermal conduction between the first thermal interface and the second thermal interface, a power electronic device having a thermal…

Apparatus for converting direct current to alternating current using a frequency converter

Granted: July 28, 2015
Patent Number: 9093919
An inverter for converting an input direct current (DC) waveform from a DC source to an output alternating current (AC) waveform for delivery to an AC grid includes an input converter, an output converter, and an active filter, each of which is electrically coupled to a bus. The bus may be a DC bus or an AC bus. The input converter is configured to convert the input DC waveform to a DC or AC bus waveform. The output converter is configured to convert the bus waveform to the output AC…

Solar cell contact formation using laser ablation

Granted: July 21, 2015
Patent Number: 9087939
The formation of solar cell contacts using a laser is described. A method of fabricating a back-contact solar cell includes forming a poly-crystalline material layer above a single-crystalline substrate. The method also includes forming a dielectric material stack above the poly-crystalline material layer. The method also includes forming, by laser ablation, a plurality of contacts holes in the dielectric material stack, each of the contact holes exposing a portion of the…

Methods for wet chemistry polishing for improved low viscosity printing in solar cell fabrication

Granted: July 14, 2015
Patent Number: 9082925
A method of fabricating a solar cell is disclosed. The method includes forming a polished surface on a silicon substrate and forming a first flowable matrix in an interdigitated pattern on the polished surface, where the polished surface allows the first flowable matrix to form an interdigitated pattern comprising features of uniform thickness and width. In an embodiment, the method includes forming the silicon substrate using a method such as, but not limited to, of diamond wire or…

Diode-included connector, photovoltaic laminate and photovoltaic assembly using same

Granted: July 14, 2015
Patent Number: 9083121
One embodiment relates to a connector that includes a diode. The diode has an anode and a cathode. The connector further includes a first electrical connection which connects to the anode, a second electrical connection which also connects to the anode, and a third electrical connection which connects to the cathode. Another embodiment relates to a photovoltaic laminate which includes a string of photovoltaic cells and three electrical conductors extending out of two discrete…

Power converter with series energy storage

Granted: July 7, 2015
Patent Number: 9077202
A power conversion system may include a first power converter to transfer power from a power source to a load, an energy storage element coupled in series between the first power converter and the load, and a second power converter to transfer energy between the energy storage element and the load. The system may be configured to provide a sinusoidal output suitable for grid-tie applications while maintaining constant input power.

Back contact sliver cells

Granted: June 30, 2015
Patent Number: 9070804
A solar cell uses a sliver of a silicon wafer as a substrate. The sliver has a front side that faces the sun during normal operation. The front side of the sliver includes a surface from along a thickness of the wafer, allowing for more efficient use of silicon. Metal contacts are formed on the back side of the sliver. The metal contacts electrically connect to the emitter and base of the solar cell, which may be formed within the sliver or be made of polysilicon. The emitter of the…

Multi-stage power inverter for power bus communication

Granted: June 23, 2015
Patent Number: 9065354
An inverter for converting an input direct current (DC) waveform from a DC source to an output alternating current (AC) waveform for delivery to an AC grid includes an input converter, an output converter, an input controller, and an output controller. The input controller is configured to control the operation of the input converter, and the output controller is configured to control the operation of the output controller. The input and output controllers are electrically isolated from…

Methods and apparatus for controlling operation of photovoltaic power plants

Granted: June 16, 2015
Patent Number: 9059604
A photovoltaic power plant includes a photovoltaic inverter that converts direct current generated by solar cells to alternating current. The output of the photovoltaic inverter is provided to a point of interconnection to a power grid. A meter at the point of interconnection may be read to detect the output of the photovoltaic inverter at the power grid. The photovoltaic power plant includes a plant controller with a state machine. The plant controller is configured to adjust setpoints…

Solar cell having an emitter region with wide bandgap semiconductor material

Granted: June 9, 2015
Patent Number: 9054255
Solar cells having emitter regions composed of wide bandgap semiconductor material are described. In an example, a method includes forming, in a process tool having a controlled atmosphere, a thin dielectric layer on a surface of a semiconductor substrate of the solar cell. The semiconductor substrate has a bandgap. Without removing the semiconductor substrate from the controlled atmosphere of the process tool, a semiconductor layer is formed on the thin dielectric layer. The…

Variable duty cycle switching with imposed delay

Granted: June 2, 2015
Patent Number: 9048740
Power conversion methods, systems, articles of manufacture, and devices are provided. The power conversion may include converting between direct current and alternating current wherein switching losses associated with latent electrical charges are reduced. Current sensing may be low-side bus reference. Solid-state implementations, code implementations, and mixed implementations are provided.

Glass-bending apparatus and method

Granted: May 26, 2015
Patent Number: 9038421
A sag-bending glass sheet mold is disclosed. The sheet mold comprises a plurality of lateral support members, a plurality of longitudinal support members arranged perpendicular to the lateral support members, each of the plurality of lateral support members extending between two of the plurality of longitudinal support members, each of the plurality of longitudinal support members having an upper surface, and the upper surfaces of each of the plurality of longitudinal support members…

Preventing harmful polarization of solar cells

Granted: May 19, 2015
Patent Number: 9035167
In one embodiment, harmful solar cell polarization is prevented or minimized by providing a conductive path that bleeds charge from a front side of a solar cell to the bulk of a wafer. The conductive path may include patterned holes in a dielectric passivation layer, a conductive anti-reflective coating, or layers of conductive material formed on the top or bottom surface of an anti-reflective coating, for example. Harmful solar cell polarization may also be prevented by biasing a region…

Crack resistant solar cell modules

Granted: May 19, 2015
Patent Number: 9035172
A crack resistant solar cell module includes a protective package mounted on a frame. The protective package includes a polyolefin encapsulant that protectively encapsulates solar cells. The polyolefin has less than five weight percent of oxygen and nitrogen in the backbone or side chain. In other words, the combined weight percent of oxygen and nitrogen in any location in the molecular structure of the polyolefin is less than five. The polyolefin also has a complex viscosity less than…

Support for solar energy collectors

Granted: May 19, 2015
Patent Number: 9035168
A solar energy collection system can include support devices made with bearings formed from sheet material. These bearings can be optionally formed so as to provide tool-less connections to their associated bearing housings. The bearings can be formed with an open configuration allowing a shaft to be inserted into an open bite of the bearing. Optionally, the bearing can be made from an ultrahigh molecular weight polyethylene plastic material. Additionally, two open-type bearing…