Shedding light on polymer solar cells: Illuminating how solvent additives improve efficiency

Researchers imaged nanoscale photocurrents in an all-polymer blend solar cell using photoconductive atomic force microscopy. Trace solvent additives were found to enhance polymer ordering and crystallization without undesirable changes in the scale of phase separation necessary for device performance. The findings explain the basis of the performance enhancement attributed to solvent additives and will accelerate research efforts aimed at establishing all-polymer blend solar cells as a viable environmentally sustainable choice.

Cosmic physics mimicked on table-top as graphene enables Schwinger effect

Researchers have succeeded in observing the so-called Schwinger effect, an elusive process that normally occurs only in cosmic events. By applying high currents through specially designed graphene-based devices, the team succeeded in producing particle-antiparticle pairs from a vacuum.

Tiny materials lead to a big advance in quantum computing

Researchers used the 2D material hexagonal boron nitride to build much smaller capacitors for superconducting qubits, enabling them to shrink the footprint of a qubit by two orders of magnitude without sacrificing performance.

Eco-friendly micro-supercapacitors using fallen leaves?

A research team has developed a graphene-inorganic-hybrid micro-supercapacitor made of leaves using femtosecond direct laser writing lithography. The advancement of wearable electronic devices is synonymous with innovations in flexible energy storage devices. Of the various energy storage devices, micro-supercapacitors have drawn a great deal of interest for their high electrical power density, long lifetimes, and short charging times.

A soft, stretchable thermometer

The next generation of soft robotics, smart clothing and biocompatible medical devices are going to need integrated soft sensors that can stretch and twist with the device or wearer. The challenge: most of the components used in traditional sensing are rigid. Now, researchers have developed a soft, self-powered thermometer that can be integrated into stretchable electronics and soft robots.

Edge processing research takes discovery closer to use in artificial intelligence networks

Researchers have successfully demonstrated proof-of-concept of using their multimodal transistor (MMT) in artificial neural networks, which mimic the human brain. This is an important step towards using thin-film transistors as artificial intelligence hardware and moves edge computing forward, with the prospect of reducing power needs and improving efficiency, rather than relying solely on computer chips.

Repairing Electronics: Electronic Candle

When visiting my parents for Christmas, my dad showed me three electronic candles that did not work anymore. He told me he had changed batteries and showed me that they did not show any signs of life.

I tried to get them to work as well, but no luck.

It sounded like a really fun device to repair, so I took them back to my lab in Oslo to try to see if I could figure out what the problem was.

When repairing electronics, you always have to start with what the problem is. Here, the problem was that nothing happened when connecting the batteries and pressing the ON switch.

When thinking about this problem I came up with two theories:

• A dead LED inside the candle
• Bad connections between batteries and the candle circuit

Checking the Contacts

I started by looking at the connections. Could the connectors have broken somehow?

To see the connectors, I had to remove the outer cover. I first did a visual inspection of the contacts. Then I used my multimeter to check for continuity between the battery touchpoints and the visible metal of the contact.

No problems found.

Opening the Candle

Next, I opened up the candle to be able to check the circuit board inside.

On the circuit board, there was a label showing that it needed 3V DC from the battery connections. So I decided to start by connecting 3V from a power supply directly to the circuit board. This way I would be able to narrow down the problem to be either on the circuit board or on the contacts before the circuit board.

I connected a 3V power supply directly to the board. And it worked!

That meant that the problem had to be somewhere before the circuit board. It had to be the contacts or the batteries.

The most obvious would be the batteries, so even though my dad told me he had used fresh batteries, I had to check. He had provided me with six AA batteries. I measured them with my multimeter and got around 1.5V on four of them, but only 0.5V on the remaining two.

An AA battery with only 0.5V can be considered to be dead. So I discarded the two 0.5V batteries and tried again with two of the good batteries.

But still nothing…

The Invisible User Error

I went back to looking at the connections.

And I did another round of testing using the continuity-tester function of my multimeter. They all looked good!

But then I noticed that the bottom part of the candle, the one I had to remove to replace the batteries, had two seemingly identical sides.

I had assumed they were identical, but at closer inspection, I saw that one side had an almost invisible connector. While the other side had no connector.

And when trying to attach the bottom part to the candle, I found that it was possible to attach it in two different ways. Only one of the ways would make the correct connection.

So once again, I inserted the batteries into the battery holder. Then I attached the bottom part making sure the connector was on the correct side.

And wouldn’t you know it – the candle worked!

I tried all three candles and they all worked when using good batteries AND connecting the bottom part the right way.

So although I didn’t actually repair anything, I found the problem. I can return the candles to my dad, and he will know how to have them working. And often the most important (and also exciting) part of repairing electronics is identifying the problem.

Copyright Build Electronic Circuits

Rubber material holds key to long-lasting, safer EV batteries

For electric vehicles (EVs) to become mainstream, they need cost-effective, safer, longer-lasting batteries that won't explode during use or harm the environment. Researchers may have found a promising alternative to conventional lithium-ion batteries made from a common material: rubber.

Fully 3D-printed, flexible OLED display

Researchers used a customized printer to fully 3D print a flexible organic light-emitting diode (OLED) display. The discovery could result in low-cost OLED displays in the future that could be widely produced using 3D printers by anyone at home, instead of by technicians in expensive microfabrication facilities.

Nematicity is a new piece in a phase diagram puzzle

A team sees stripes in samples of twisted double bilayer graphene, indicating the presence of a nematic phase characterized by broken rotational symmetry.

Mass production of revolutionary computer memory moves closer with ULTRARAM™ on silicon wafers for the first time

A pioneering type of patented computer memory known as ULTRARAM™ has been demonstrated on silicon wafers in what is a major step towards its large-scale manufacture. ULTRARAM™ is novel type of memory with extraordinary properties. It combines the non-volatility of a data storage memory, like flash, with the speed, energy-efficiency and endurance of a working memory, like DRAM. To do this it utilizes the unique properties of compound semiconductors, commonly used in photonic devices such as LEDS, laser diodes and infrared detectors, but not in digital electronics, which is the preserve of silicon.

The first topological acoustic transistor

Researchers have designed and simulated the first topological acoustic transistors -- with sound waves instead of electrons -- and proposed a connection architecture to form a universal logic gate that can switch the flow of sound on and off.

Sustainable silk material for biomedical, optical, food supply applications

Researchers discuss the properties of silk and recent and future applications of the material. It has been used in drug delivery and is ideal for wearable and implantable health monitoring sensors. Silk is also useful in optics and electronics and more recently has come to the forefront of sustainability research. The use of silk coatings may also reduce food waste, which is a significant component of the global carbon footprint.

3D semiconductor particles offer 2D properties

Researchers have discovered that the junctures at the facet edges of 3D semiconductor particles have 2D properties, which can be leveraged for photoelectrochemical processes -- in which light is used to drive chemical reactions -- that can boost solar energy conversion technologies.