Consolidated tables showing an extensive listing of the highest independently confirmed efficiencies for solar cells and modules are presented. Guidelines for inclusion of results into these tables are outlined and new entries since July 2014 are reviewed. URI: http://onlinelibrary.wiley.com/doi/10.1002/pip.2573/pdf [1] Authors: GREEN Martin A. EMERY Keith HISHIKAWA Y. WARTA W. DUNLOP Ewan Publication Year: 2015 Type: Articles in Journals

Solar Cell Efficiency Tables (Version 45)

Recent developments in photovoltaic materials have led to continual improvements in their efficiency. We review the electrical characteristics of 16 widely studied geometries of photovoltaic materials with efficiencies of 10 to 29%. Comparison of these characteristics to the fundamental limits based on the Shockley-Queisser detailed-balance model provides a basis for identifying the key limiting factors, related to efficient light management and charge carrier collection, for these materials. Prospects for practical application and large-area fabrication are discussed for each material.

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Photovoltaic materials: Present efficiencies and future challenges

https://onlinelibrary.wiley.com/doi/pdf/10.1002/pip.2909

Solar cell efficiency tables (version 50)

Solar cell efficiency tables (version 51)

/pdf/solar-cell-efficiency-tables-version-41-3knpfpolwl.pdf

Solar cell efficiency tables (version 41)

Alta Devices, Inc. has fabricated a thin-film GaAs device on a flexible substrate with an independently-confirmed solar energy conversion efficiency of 27.6%, under AM1.5G solar illumination at 1 sun intensity. This represents a new record for single-junction devices under non-concentrated sunlight. This surpasses the previous record, for conversion efficiency of a single-junction device under non-concentrated light, by more than 1%. This is due largely to the high open-circuit voltage (V oc ) of this device. The high V oc results from precise control of the dark current. The fact that this record result has been achieved with a thin-film shows that, for GaAs material systems, the majority of the growth substrate is not needed for device performance. This allows one to consider amortizing the potentially high cost of a GaAs growth substrate by growing a thin-film, lifting it off, and reusing the same substrate multiple times. This technology therefore has the potential to be a novel high-performance, thin-film option for terrestrial photovoltaics.

27.6% Conversion efficiency, a new record for single-junction solar cells under 1 sun illumination

Alta Devices, Inc. has previously reported on single-junction thin-film GaAs photovoltaic devices on flexible substrates with efficiencies up to 28.8% under AM1.5G solar illumination at 1-sun intensity. Here, we show that the same technology platform can be extended to tandem devices that are capable of even higher efficiencies: so far up to 30.8%. Specifically, here, we report on a lattice-matched, series-connected, two-junction device with InGaP as the light-absorbing material of the top cell and GaAs as the absorber in the bottom cell. The material is grown by metallorganic chemical vapor deposition, and then, the device is lifted off by the epitaxial liftoff (ELO) process, as previously reported. This demonstrates that ELO is not only capable of record-setting single-junction performance but capable of achieving world-class efficiency with a multijunction architecture as well.

Flexible Thin-Film Tandem Solar Cells With >30% Efficiency

Embodiments of the invention generally relate to a chemical vapor deposition system and related method of use. In one embodiment, the system includes a reactor lid assembly having a body, a track assembly having a body and a guide path located along the body, and a heating assembly operable to heat the substrate as the substrate moves along the guide path. The body of the lid assembly and the body of the track assembly are coupled together to form a gap that is configured to receive a substrate. In another embodiment, a method of forming layers on a substrate using the chemical vapor deposition system includes introducing the substrate into a guide path, depositing a first layer on the substrate and depositing a second layer on the substrate, while the substrate moves along the guide path; and preventing mixing of gases between the first deposition step and the second deposition step.

Methods and apparatus for a chemical vapor deposition reactor

Methods and apparatus are provided for converting electromagnetic radiation, such as solar energy, into electric energy with increased efficiency when compared to conventional solar cells. In one embodiment of a photovoltaic (PV) device, the PV device generally includes an n-doped layer and a p+-doped layer adjacent to the n-doped layer to form a p-n layer such that electric energy is created when electromagnetic radiation is absorbed by the p-n layer. The n-doped layer and the p+-doped layer may compose an absorber layer having a thickness less than 500 nm. Such a thin absorber layer may allow for greater efficiency and flexibility in PV devices when compared to conventional solar cells.

Thin absorber layer of a photovoltaic device

Methods and apparatus are provided for converting electromagnetic radiation, such as solar energy, into electric energy with increased efficiency when compared to conventional solar cells. A photovoltaic (PV) device may incorporate front side and/or back side light trapping techniques in an effort to absorb as many of the photons incident on the front side of the PV device as possible in the absorber layer. The light trapping techniques may include a front side antireflective coating, multiple window layers, roughening or texturing on the front and/or the back sides, a back side diffuser for scattering the light, and/or a back side reflector for redirecting the light into the interior of the PV device. With such light trapping techniques, more light may be absorbed by the absorber layer for a given amount of incident light, thereby increasing the efficiency of the PV device.

Gregg Higashi

Papers

27.6% Conversion efficiency, a new record for single-junction solar cells under 1 sun illumination

Flexible Thin-Film Tandem Solar Cells With >30% Efficiency

Methods and apparatus for a chemical vapor deposition reactor

Thin absorber layer of a photovoltaic device

Photovoltaic device with increased light trapping