The efficiency of silicon solar cells has a large influence on the cost of most photovoltaics panels. Here, researchers from Kaneka present a silicon heterojunction with interdigitated back contacts reaching an efficiency of 26.3% and provide a detailed loss analysis to guide further developments.

Silicon heterojunction solar cell with interdigitated back contacts for a photoconversion efficiency over 26

The crystalline silicon heterojunction structure adopted in photovoltaic modules commercialized as Panasonic's HIT has significantly reduced recombination loss, resulting in greater conversion efficiency. The structure of an interdigitated back contact was adopted with our crystalline silicon heterojunction solar cells to reduce optical loss from a front grid electrode, a transparent conducting oxide (TCO) layer, and a-Si:H layers as an approach for exceeding the conversion efficiency of 25%. As a result of the improved short-circuit current (J
 sc
), we achieved the world's highest efficiency of 25.6% for crystalline silicon-based solar cells under 1-sun illumination (designated area: 143.7 cm
 2
).

Achievement of More Than 25% Conversion Efficiency With Crystalline Silicon Heterojunction Solar Cell

Exceeding conversion efficiency of 26% by heterojunction interdigitated back contact solar cell with thin film Si technology

A method and an apparatus for transmitting broadcast signals thereof are disclosed. The method for transmitting broadcast signals includes encoding DP data according to a code rate, wherein the encoding further includes LDPC encoding the DP data according to the code rate, bit interleaving the LDPC encoded DP data, mapping the bit interleaved DP data onto constellations, MIMO (Multi Input Multi Output) encoding the mapped DP data, and time interleaving the MIMO encoded DP data; building at least one signal frame by arranging the encoded DP data; and modulating data in the built signal frame by OFDM method and transmitting the broadcast signals having the modulated data, wherein the step of modulating includes inserting CPs in the built signal frame based on a CP set which includes information about locations of CPs, wherein the CP set is defined based on FFT size.

Apparatus for transmitting broadcast signals, apparatus for receiving broadcast signals, method for transmitting broadcast signals and method for receiving broadcast signals

A nanowire array is described herein. The nanowire array comprises a substrate and a plurality of nanowires extending essentially vertically from the substrate; wherein: each of the nanowires has uniform chemical along its entire length; a refractive index of the nanowires is at least two times of a refractive index of a cladding of the nanowires. This nanowire array is useful as a photodetector, a submicron color filter, a static color display or a dynamic color display.

Light absorption and filtering properties of vertically oriented semiconductor nano wires

A solar cell and a method for manufacturing the same are disclosed. The solar cell includes a substrate of a first conductive type, an anti-reflection layer that is positioned on the substrate and is formed of a transparent conductive oxide material, a plurality of emitter layers on the substrate, the plurality of emitter layers being of a second conductive type opposite the first conductive type, a plurality of first electrodes on the plurality of emitter layers, and a plurality of second electrodes that are electrically connected to the substrate and are positioned to be spaced apart from the plurality of first electrodes. The first electrodes and the second electrodes are positioned on the same surface of the substrate.

Solar cell and method for manufacturing the same

Analysis of a-Si:H/TCO contact resistance for the Si heterojunction back-contact solar cell

Effects of ITO precursor thickness on transparent conductive Al doped ZnO film for solar cell applications

Al-doped ZnO (AZO) film was continuously deposited by DC magnetron sputtering using pure Ar on a thin AZO seed layer prepared using an approximately 4% dilution of oxygen with Ar. X-ray diffraction measurements showed that the AZO film grown on the seed layer exhibited a much higher crystallinity and larger grain size than that without the seed layer. The electrical properties such as resistivity and Hall mobility were improved. The average visible transmittance was increased from 81.6 to 86.2%, and near infrared (NIR) transmittance was increased from 76.0 to 84.4% by employing the seed layer. The haze value characterizing the light scattering property was significantly increased from 59.4 to 89.5% in the visible region by the seed layer, and it was increased from 15.1 to 50.8% in the NIR region. Surface topography analysis showed that the bilayer AZO film had larger craters allowing for improvement of the light scattering properties than the conventional AZO film without the seed layer.

Highly Transparent and High Haze Bilayer Al-Doped ZnO Thin Film Employing Oxygen-Controlled Seed Layer

The present invention relates to a photovoltaic conversion apparatus including a by-pass diode and a manufacturing method thereof. The photovoltaic conversion apparatus of the present invention comprises at least one unit solar cell module configured of at least one unit solar cell; and a by-pass solar cell module including at least one solar cell electrically connected to the unit solar cell to by-pass current. According to the present invention, a photovoltaic conversion apparatus having high photoelectric conversion efficiency can be manufactured. Also, the photovoltaic conversion apparatus will contribute to earths environmental conservation as the next clean energy source and can be directly applied to private facilities, public facilities, military facilities, etc., to create enormous economic value.

Kwang-Sun Ji

Papers

Solar cell and method for manufacturing the same

Analysis of a-Si:H/TCO contact resistance for the Si heterojunction back-contact solar cell

Effects of ITO precursor thickness on transparent conductive Al doped ZnO film for solar cell applications

Highly Transparent and High Haze Bilayer Al-Doped ZnO Thin Film Employing Oxygen-Controlled Seed Layer

Thin-film type solar cell including by-pass diode and manufacturing method thereof