The invention relates to a back-side contact solar cell including a semiconductor substrate, in particular a silicon wafer, including a front side and a back side, the solar cell having electrodes of a first polarity and electrodes of a second polarity on the back side, wherein a tunnel layer and a highly doped silicon layer are positioned under the electrodes of a first polarity, and the electrodes of the second polarity make direct electrical and mechanical contact with the semiconductor substrate.

The invention relates to a back-side contact solar cell including a semiconductor substrate, in particular a silicon wafer, including a front side and a back side, the solar cell having electrodes of a first polarity and electrodes of a second polarity on the back side, wherein a tunnel layer and a highly doped silicon layer are positioned under the electrodes of a first polarity, and the electrodes of the second polarity make direct electrical and mechanical contact with the semiconductor substrate.

A solar cell includes: an n-type first amorphous silicon layer provided on a first main surface of a crystalline silicon substrate; an amorphous silicon oxide layer provided on a first main surface of the first amorphous silicon layer; and an n-type fine crystal silicon layer provided on a first main surface of the amorphous silicon oxide layer. An oxygen atom concentration in the first amorphous silicon layer, the amorphous silicon oxide layer, and the fine crystal silicon layer has a maximum value in the amorphous silicon oxide layer with a thickness direction.

A solar cell includes: an n-type first amorphous silicon layer provided on a first main surface of a crystalline silicon substrate; an amorphous silicon oxide layer provided on a first main surface of the first amorphous silicon layer; and an n-type fine crystal silicon layer provided on a first main surface of the amorphous silicon oxide layer. An oxygen atom concentration in the first amorphous silicon layer, the amorphous silicon oxide layer, and the fine crystal silicon layer has a maximum value in the amorphous silicon oxide layer with a thickness direction.

Photovoltaic devices with very high breakdown voltages are described herein. Typical commercial silicon photovoltaic devices have breakdown voltages below 50-100 volts (V). Even though such devices have bypass diodes to prevent photovoltaic cells from going into breakdown, the bypass diodes have high failure rates, leading to unreliable devices. A high-efficiency silicon photovoltaic cell is provided with very high breakdown voltages. By combining a device architecture with very low surface recombination and silicon wafers with high bulk resistivity (above 10 ohms centimeter (Ω-cm)), embodiments described herein achieve breakdown voltages close to 1000 V. These photovoltaic cells with high breakdown voltages improve the reliability of photovoltaic devices, while reducing their design complexity and cost.

Photovoltaic devices with very high breakdown voltages are described herein. Typical commercial silicon photovoltaic devices have breakdown voltages below 50-100 volts (V). Even though such devices have bypass diodes to prevent photovoltaic cells from going into breakdown, the bypass diodes have high failure rates, leading to unreliable devices. A high-efficiency silicon photovoltaic cell is provided with very high breakdown voltages. By combining a device architecture with very low surface recombination and silicon wafers with high bulk resistivity (above 10 ohms centimeter (Ω-cm)), embodiments described herein achieve breakdown voltages close to 1000 V. These photovoltaic cells with high breakdown voltages improve the reliability of photovoltaic devices, while reducing their design complexity and cost.

A high-voltage switch is adapted for use as a medium-voltage direct current circuit breaker, which provides a low-cost, small-footprint device to mitigate system faults. In one example, a method for operating a wideb and optical device includes illuminating the wide bandgap optical device with a light within a first range of wavelengths and a first average intensity, allowing a current to propagate therethrough without substantial absorption of the current, illuminating the wide bandgap optical device with light within the first range of wavelengths and a second average intensity that is lower than the first average intensity to allow a sustained current flow though the wide bandgap optical device, and illuminating the wide bandgap optical device with light within a second range of wavelengths to stop or substantially restrict propagation of the current through the wide gap material.

A high-voltage switch is adapted for use as a medium-voltage direct current circuit breaker, which provides a low-cost, small-footprint device to mitigate system faults. In one example, a method for operating a wideb and optical device includes illuminating the wide bandgap optical device with a light within a first range of wavelengths and a first average intensity, allowing a current to propagate therethrough without substantial absorption of the current, illuminating the wide bandgap optical device with light within the first range of wavelengths and a second average intensity that is lower than the first average intensity to allow a sustained current flow though the wide bandgap optical device, and illuminating the wide bandgap optical device with light within a second range of wavelengths to stop or substantially restrict propagation of the current through the wide gap material.

An avalanche diode including a gain region and a readout structure including an n-type (p-type) region having electrically isolated segments each including implanted regions; a p-type (n-type) region; and a first electrode on each of the segments. The gain region includes a p-n junction buried between the n-type region and the p-type region: an n.sup.+-type region having a higher n-type dopant density than the n-type region; a p.sup.+-type region having a higher p-type dopant density than the p-type region; and the p-n junction between the n.sup.+-type region and the p.sup.+-type region. A bias between the first electrodes and a second electrode (ohmically contacting the p-type (n-type) region) reverse biases the p-n junction. Electrons generated in response to electromagnetic radiation or charged particles generate additional electrons m the gain region through impact ionization but the segmented region comprises a low field region isolating the gain region from the first electrodes.

Disclosed is a solar cell including a semiconductor substrate, and a dopant layer disposed over one surface of the semiconductor substrate and having a crystalline structure different from that of the semiconductor substrate, the dopant layer including a dopant. The dopant layer includes a plurality of semiconductor layers stacked one above another in a thickness direction thereof, and an interface layer interposed therebetween. The interface layer is an oxide layer having a higher concentration of oxygen than that in each of the plurality of semiconductor layers.