Heterostructured photoconductors based on hybrid perovskites and 2D transition-metal dichalcogenides are fabricated and characterized. Due to the superior properties of CH NH PbI and WS , as well as the efficient interfacial charge transfer, such photoconductors show high performance with on/off ratio of ≈105 and responsivity of ≈17 A W−1. Furthermore, the response times of the heterostructured photoconductors are four orders of magnitude faster compared to the counterpart of a perovskite single layer.
Thermex Metal Treating Ltd., Edmonton, is expanding its capacity with the purchase of a Seco Warwick gas nitriding system with vertical pit-style loading and proprietary ZeroFlow control technology. This new system features precise control of the gas nitriding process by using continuous in-process atmosphere analysis to provide ongoing feedback and information. This allows for close control of properties such as case depth and compound (white) layer formation, including control of the thickness and phase of the white layer. A key feature of this new system is a significant reduction in ammonia gas consumption, which leads to reduced emissions. The work zone size is 39 inches diameter and 75 inches deep. A maximum gross weight of 6600 pounds can be processed in a load. ZeroFlow control is based on nitriding with a single-component atmosphere – raw ammonia (NH ). The adjustment of nitriding atmosphere chemical composition, and therefore the control of nitriding potential, is done only by analyzing and metering ammonia into the furnace. The ZeroFlow method is characterized by much lower consumption and emission of gases, and it requires a simpler control system, while allowing for forming the hardened layer phase structure with the same precision as processes with more complex two-component atmospheres. Thermex offers a wide range of ferrous metal heat treating processes and services in Western Canada from its base in Edmonton. The purchase of this state-of-the-art equipment is in keeping with the company's ongoing commitment to continuous improvement, integration of new technology, and high quality customer service. According to Thermex president Norm Hanson, "Combined with Seco Warwick's R&D testing capabilities and its experience in gas nitriding, we felt this was our best option to offer precise nitriding solutions for our customers and our large load requirements."
News Article | August 21, 2016
We promote solar power quite a lot here on CleanTechnica. We’ve actually published nearly 10,000 articles on the topic. We often combine the benefits of utility-scale solar power and rooftop solar power when discussing many of the great advantages that solar offers. Even when we do specifically write about the benefits of rooftop solar power, we typically focus on the technical benefits (less need for transmission infrastructure, greater grid stability and security, reduced whole electricity costs due to solar providing electricity at times of high demand, etc.). However, there are some huge societal benefits that come from distributed rooftop solar power and community solar power aside from the technical ones. Following my recently revived interest in spending more time on the “human side of cleantech” (see this, this, this, this, this, this, this, this, and this.), that’s what this article is again delving into. It’s a matter of political and philosophical debate, but I agree with the idea that society is generally better off when socioeconomic and political power are distributed. (Granted, a benevolent dictator can be a wonderful gift for a society, but most dictatorships don’t tend to be very benevolent from what I’ve seen.) While we do live in a somewhat democratic society (in the US, Canada, UK, Europe, Australia, India, Korea, Japan, or wherever you are probably reading from), there’s no doubt that money = power, and people with more money or representing more money have more power in politics and society. With regard to this matter, we often think of powerful people and companies in the telecommunications, media, banking, and real estate industries. Clearly, though, these aren’t the only ones trying to steer more cash to their executives than to society as a whole. Of course, with many utilities being regulated monopolies, these are powerful giants as well (no pun intended). Despite the fact that they are regulated, the vast majority of us can’t name the people who regulate them, and there is rampant corruption in the sector. Largely, we don’t even know what they’re doing. I think we typically take utilities for granted and leave their work almost invisible — they’re there, we have to pay them to keep the lights and computers on, someone is watching over them to make sure they don’t fleece us (too much), etc. A more obvious “enemy of the societal good” is the fossil energy industry. Burning coal and natural gas kills millions of people prematurely every year. We somehow accept burning these fossils as a necessity of modern life (though, given the state of clean technologies like solar and EVs, we no longer should), but we also know that these industries work hard to not clean up their processes and emit less pollution. They lobby government and fight huge wars against regulation with millions and millions of dollars that could have just gone toward protecting more lives from pollution. But hey, what can we do? As I highlighted recently, in the USA, the coal, oil, and natural gas industries spend a ridiculous amount of money trying to put Republicans into office. In return (whether with full awareness and lack of ethics or more subconsciously), Republican Congresspeople and many state-level politicians — to the detriment of their actual constituents — routinely vote against coal, oil, and natural gas regulations; vote against protecting our clean water supply and our air; vote against policies to stop global warming; and essentially vote for death over life. Here’s just one example of where their money goes, via the Climate Science Defense Fund (h/t Bob Wallace): Last week, roughly 20 U.S. Senators spoke out against the “web of denial” in climate change, calling out organizations that have sought to deceive the public about global warming. One focal point was coal–funded E&E Legal, an organization we have repeatedly battled in court because of its relentless attacks on climate scientists. Watch Senator Shaheen (D-NH) explain how E&E Legal’s “specialty is harassing individual climate scientists and researchers” by bringing lawsuits “to disrupt important academic research that may help us anticipate, avoid, or mitigate the impacts of global warming.” (Main discussion of E&E Legal starts at about 9:33.) The blockade against clean air, clean water, and a livable climate has become such a core part of the Republican Party that the only ways to make progress at the moment are basically to get a Democratic supermajority in federal politics, for a Democratic president to use executive orders, or for extremely well executed (and probably lucky) dealmaking. The situation with utilities is a bit more complicated. Utilities aren’t by default human-killing entities. However, they are often investor-owned monopolies that are greedily interested in squeezing as much cash out of ratepayers as possible. They enjoy high profit margins, and they make money on a combination of infrastructure investments, utility-owned power plants, and customer service. In general, if they “have to” spend more on infrastructure, they are going to make more money and send more back to their investors. If they can charge customers for more things (e.g., putting solar panels on their roofs and connecting them to the grid), they make more money and send more back to investors. If there’s no more need to expand the grid and consumers are using less electricity, utility revenue shrinks — not the type of thing an investor utility executive is aiming for. So, utilities fight distributed solar power, in obvious as well as underhanded ways. As rooftop solar power takes more of the market from fossil fuels, that keeps more money away from fossil fuel lobbyists and politicians, which inherently weakens their political power to some extent. However, beyond that, rooftop solar owners, people invested in community solar projects, and people interested in making such investments automatically become more open to and invested in a clean energy future without pollution. That political capital is more powerful because their policy preference is more powerful than a simple (but not passionate) preference for clean energy; a preference that isn’t tied to one’s personal assets, investments, and planned investments. As more people become personally invested in solar, the political pressure for the rest of the country to switch to clean energy and stop subsidizing coal and natural gas grows. The political pressure for climate action grows. Additionally, people who go solar are likely to learn quite a bit more about energy — not everyone will, but many will get caught up a bit on energy information they never knew before. That greater understanding of energy matters, in general, and especially solar energy matters will make them more attentive to obviously false claims that politicians make because of their ties to the fossil fuel industry. It will make them less tolerant of such lies, and will make them more skeptical of the politicians and media personalities who push them. Naturally, this will most hurt the politicians who are “bought” by the fossil fuel industry, weakening the “return on investment” the polluting industry gets from such politicians. This will also weaken opposition to broad and strong climate action. The politicians advocating that we delay turning off the oven will have less and less support. Also, as more people go solar, they will become more inclined to believe in the science that tells us global warming is an existential threat to society and we should act fast — they have already taken a big step forward lightening their climate footprint (whether that was part of the impetus for going solar or not), so they will be more willing to accept the need for such action and the moral benefits of being a cleantech leader. It’s basically a very similar story with utilities, but on another level much of the time. Utilities influence national policies, but they also tend to have a strong influence on regional and state policies and the regulators who oversee the industry. As more people invest in distributed solar, these solar owners/investors will want to see that option supported, not opposed via solar fees, complicated and slow permitting, reduced or cancelled net metering policies, etc. Even if utilities have a lot of money and lobbyists, a large number of solar homeowners creates a highly invested and informed subculture that will oppose policies that harm the solar industry. The short summary is that, as electricity generation is less centralized, the voting public will be less likely to put up with policy decisions on this matter that benefit a small minority of rich people to the detriment of most of society. The voting public will be less likely to accept unnecessary cancer, heart disease, and premature death. Overall, the voting public will be less likely to accept centralized political power that benefits a few while harming the rest, and that effect makes the benefits of democratized solar power even more valuable and broader than discussions of electricity markets and emissions typically imply. Images 1 & 4 by Marcacci Communications | 350.org. Images 2 & 3 by Open Secrets. Images 5–8 by Cleantech Revolution Tour | CleanTechnica | GridHub Drive an electric car? Complete one of our short surveys for our next electric car report. Keep up to date with all the hottest cleantech news by subscribing to our (free) cleantech newsletter, or keep an eye on sector-specific news by getting our (also free) solar energy newsletter, electric vehicle newsletter, or wind energy newsletter.
Monolayer transition-metal dichalcogenides (TMDCs) have recently emerged as promising candidates for advanced photonic and valleytronic applications due to their unique optoelectronic properties. However, the low luminescence efficiency of monolayer TMDCs has significantly hampered their use in these fields. Here it is reported that the photoluminescence efficiency of monolayer WS can be remarkably enhanced up to fourfold through the fluorination, surpassing the reported performance of molecular and/or electrical doping methods. Its degree is easily controlled by changing the fluorine plasma duration time and can also be reversibly tuned via additional hydrogen plasma treatment, allowing for its versatile tailoring for interfacial band alignment and customized engineering. The striking photoluminescence improvement occurs via a substantial transition of trions to excitons as a result of the strong electron affinity of fluorine dopants, and the fluorination enables unprecedented detection of n-type NH gas in WS due to changed excitonic dynamics showing excellent sensitivity (at least down to 1.25 ppm). This work provides valuable strategies and insights into exciton physics in monolayer TMDCs, opening up avenues toward highly-efficient 2D light emitters, photovoltaics, nanosensors, and optical interconnects.
An organic–inorganic halide CH NH SnI perovskite with significantly improved structural stability is obtained via pressure-induced amorphization and recrystallization. In situ high-pressure resistance measurements reveal an increased electrical conductivity by 300% in the pressure-treated perovskite. Photocurrent measurements also reveal a substantial enhancement in visible-light responsiveness. The mechanism underlying the enhanced properties is shown to be associated with the pressure-induced structural modification.