Explore the vast range of titles available.

CdTe is the leading commercial thin film photovoltaic technology with current record laboratory efficiency (22.1%). However, there is much potential for progress toward the Shockley‐Queisser limit (32%). The best CdTe devices have short‐circuit current close to the limit but open‐circuit voltage has much room for improvement. Back contact optimization is likely to play a key role in any improvement. Back contact material choice is also influenced by their applicability in more complex architectures such as bifacial and tandem solar cells, where high visible and/or near‐infrared transparency is required in conjunction with their electrical properties. The CdTe research community has employed many back contact materials and processes to realize them. Excellent reviews of back contacts were published by McCandless and Sites (2011) and Kumar and Rao (2014). There have been numerous publications on CdTe back contacts since 2014. This review includes both recent and older literature to give a comprehensive picture. It includes a categorization of back contact interface materials into groups such as oxides, chalcogenides, pnictides, halides, and organics. The authors attempt to identify the more promising material groups. Attention is drawn to parallels with back contact materials used on other thin film photovoltaics such as perovskites and kesterites. A comprehensive review of back contact material performance when used in thin film CdTe‐based solar cells is given. Back contacts are one key component in improving the efficiency and stability of this leading commercial thin film technology toward 25% efficiency. Back contact materials are grouped into categories, and solar cell parameters are compared using multiple tables. Many individual material comparisons are made to solar cells made in perovskite and kesterite technologies using the same or similar hole transport layers.

The deposition of thin Cadmium Telluride (CdTe) layers was performed by a chamberless metalorganic chemical vapour deposition process, and trends in growth rates were compared with computational fluid dynamics numerical modelling. Dimethylcadmium and diisopropyltelluride were used as the reactants, released from a recently developed coating head orientated above the glass substrate (of area 15 × 15 cm2). Depositions were performed in static mode and dynamic mode (i.e., over a moving substrate). The deposited CdTe film weights were compared against the calculated theoretical value of the molar supply of the precursors, in order to estimate material utilisation. The numerical simulation gave insight into the effect that the exhaust’s restricted flow orifice configuration had on the deposition uniformity observed in the static experiments. It was shown that > 59% of material utilisation could be achieved under favourable deposition conditions. The activation energy determined from the Arrhenius plot of growth rate was ~ 60 kJ/mol and was in good agreement with previously reported CdTe growth using metalorganic chemical vapour deposition (MOCVD). Process requirements for using a chamberless environment for the inline deposition of compound semiconductor layers were presented.

Photovoltaics (PVs) are a critical technology for curbing growing levels of anthropogenic greenhouse gas emissions, and meeting increases in future demand for low-carbon electricity. In order to fulfil ambitions for net-zero carbon dioxide equivalent (CO2eq) emissions worldwide, the global cumulative capacity of solar PVs must increase by an order of magnitude from 0.9 TWp in 2021 to 8.5 TWp by 2050 according to the International Renewable Energy Agency, which is considered to be a highly conservative estimate. In 2020, the Henry Royce Institute brought together the UK PV community to discuss the critical technological and infrastructure challenges that need to be overcome to address the vast challenges in accelerating PV deployment. Herein, we examine the key developments in the global community, especially the progress made in the field since this earlier roadmap, bringing together experts primarily from the UK across the breadth of the photovoltaics community. The focus is both on the challenges in improving the efficiency, stability and levelized cost of electricity of current technologies for utility-scale PVs, as well as the fundamental questions in novel technologies that can have a significant impact on emerging markets, such as indoor PVs, space PVs, and agrivoltaics. We discuss challenges in advanced metrology and computational tools, as well as the growing synergies between PVs and solar fuels, and offer a perspective on the environmental sustainability of the PV industry. Through this roadmap, we emphasize promising pathways forward in both the short- and long-term, and for communities working on technologies across a range of maturity levels to learn from each other.

  [...]the Supreme Court has made clear in a special, second ruling that the case is applicable to every form of birth control.

  [...]to say that this election demonstrates \"shale gas is the winner\" is like saying President George W. Bush's re-election was a mandate for unpopular policies like extending the Iraq war or privatizing Social Security.

  Rep. Richard Hanna voted repeatedly to maintain subsidies for the oil and gas industry, but called investments in renewable energy \"pathetic.\"

  The fact that an even smaller portion of Planned Parenthood's funding is subject to the appropriation process (the bulk comes through Medicare, Medicaid and the Child Health Insurance Program) demonstrates the political grandstanding behind this potential budget crisis.

The fact that an even smaller portion of Planned Parenthood's funding is subject to the appropriation process (the bulk comes through Medicare, Medicaid and the Child Health Insurance Program) demonstrates the political grandstanding behind this potential budget crisis.

  [...]the Supreme Court has made clear in a special, second ruling that the case is applicable to every form of birth control.

[...]the Supreme Court has made clear in a special, second ruling that the case is applicable to every form of birth control.