Phosphorus-arsenic nanoribbons may improve solar cell performance

UK reearchers have created a new material that purportedly has the potential to improve the flow of charge through solar cells and enhance their efficiency. The material consists of phosphorus alloyed with arsenic.

“The study shows that alloying is a powerful tool for controlling the properties and thus applications and potential of this growing nanomaterial family,” said researcher Adam Clancy.

The creation of arsenic-phosphorus alloy nanoribbons (AsPNRs) dates back to the group's past work. In 2019, the researchers discovered phosphorus nanoribbons.

“However, phosphorus-only materials do not conduct electricity very well, hindering their usage for certain applications,” they stated.

To tackle this problem, the research team alloyed phosphorus with its neighboring element, arsenic. They initiated the process by using a commercially available black arsenic phosphorus (bAsP) alloy. Submerging this alloy into a lithium electride ammonia solution led to the formation of compounds containing phosphorus with arsenic precursors, commonly referred to as bAsP, along with lithium.

Following this process, the academics dispersed the compounds in amidic solvents and created the AsPNRs. Then they analyzed the properties of the AsPNRs and found they have high hole mobilities. As holes are the opposite partners to electrons in electrical transport, their improvement helps electrical current move more efficiently.

The researchers have further specified that the AsPNRs are reaching the highly electrically conductive state at above 130 kelvin. In addition to the high hole mobilities, their conductivity is also due to a small energy bandgap of only 0.035 eV and their paramagnetic nature.

“AsPNRs can be used in applications where the low electrical conductivity of quasi-1D phosphorene nanoribbons hinders their application, such as energy storage electrodes,” the scientists concluded. “Beyond, their small band gap, magnetism, and high hole mobilities make them ideal candidates for next generation near-infrared detectors, quantum computing, and charge carrier layers in solar cells, respectively.”

They described their findings in “Production of Magnetic Arsenic–Phosphorus Alloy Nanoribbons with Small Band Gaps and High Hole Conductivities,” which was recently published in the Journal of the American Chemical Society. The research group includes scientists from University College London, University of Cambridge, Queen Mary University of London, and University of Bristol.