{"id":102740,"date":"2024-10-24T02:23:00","date_gmt":"2024-10-24T00:23:00","guid":{"rendered":"https:\/\/www.sonnenseite.com\/?p=102740"},"modified":"2024-10-23T12:24:17","modified_gmt":"2024-10-23T10:24:17","slug":"towards-better-solar-cells-exploring-an-anomalous-phenomenon-of-electricity-generation","status":"publish","type":"post","link":"https:\/\/www.sonnenseite.com\/en\/science\/towards-better-solar-cells-exploring-an-anomalous-phenomenon-of-electricity-generation\/","title":{"rendered":"Towards Better Solar Cells: Exploring an Anomalous Phenomenon of Electricity Generation"},"content":{"rendered":"\n

Researchers explore the bulk photovoltaic effect in a promising material for next-generation solar harvesting technologies.<\/p>\n\n\n\n

The bulk photovoltaic (BPV) effect is an uncommon phenomenon that may enable certain materials to outperform the conventional p\u2013n junctions used in solar cells. In a recent study, researchers from Japan have experimentally demonstrated the BPV effect in alpha-phase indium selenide (\u03b1-In2<\/sub>Se3<\/sub>) for the first time along the out-of-plane direction, validating previous theoretical predictions. The remarkable conversion efficiency recorded in their \u03b1-In2<\/sub>Se3<\/sub> device signals a promising advancement for future solar cell technologies and photosensors.<\/p>\n\n\n\n

A firm understanding of the photovoltaic effect, by which light can be converted into useful electrical energy, lies at the core of solar cell design and development. Today, most solar cells employ p\u2013n junctions, leveraging the photovoltaic effect that occurs at the interface of different materials. However, such designs are constrained by the Shockley\u2013Queisser limit, which puts a hard cap on their theoretical maximum solar conversion efficiency and imposes a tradeoff between the voltage and current that can be produced via the photovoltaic effect.<\/p>\n\n\n\n

However, certain crystalline materials exhibit an intriguing phenomenon known as the bulk photovoltaic (BPV) effect. In materials lacking internal symmetry, electrons excited by light can move coherently in a specific direction instead of returning to their original positions. This results in what is known as \u201cshift currents,\u201d leading to the generation of the BPV effect. Although experts have predicted alpha-phase indium selenide (\u03b1-In2<\/sub>Se3<\/sub>) to be a possible candidate to demonstrate this phenomenon, it hasn\u2019t yet been experimentally investigated.<\/p>\n\n\n\n

To fill this knowledge gap, a research team from Japan led by Associate Professor Noriyuki Urakami from Shinshu University set out to explore the BPV effect in \u03b1-In2<\/sub>Se3.<\/sub> Their findings were published in Volume 125, Issue 7 of Applied Physics Letters<\/em><\/a> on August 12, 2024 and made available online on August 14, 2024.<\/p>\n\n\n\n

\u201cThis material has recently become a hot topic in the field of condensed matter physics, as it might be able to generate a shift current. Our study is the first to experimentally demonstrate this prediction<\/em>,\u201d shares Prof. Urakami.<\/p>\n\n\n\n

First, the researchers produced a layered device composed of a thin \u03b1-In2<\/sub>Se3<\/sub> layer sandwiched between two transparent graphite layers. These graphite layers served as electrodes and were connected to a voltage source and an ammeter to measure any generated currents upon light irradiation. Notably, the team employed this specific arrangement of layers because they focused on the shift currents occurring in the out-of-plane direction in the \u03b1-In2<\/sub>Se3<\/sub> layer.<\/p>\n\n\n\n

After testing with different external voltages and incident light of various frequencies, the researchers verified the existence of shift currents in the out-of-plane direction, confirming the abovementioned predictions. The BPV effect occurred throughout a wide range of light frequencies.<\/p>\n\n\n\n

Most importantly, the researchers gauged the potential of the BPV effect in \u03b1-In2<\/sub>Se3<\/sub> and compared it to that in other materials. \u201cOur \u03b1-In2<\/sub>Se3<\/sub> device demonstrated a quantum efficiency several orders of magnitude higher than other ferroelectric materials, and a comparable one to that of low-dimensional materials with enhanced electric polarization,<\/em>\u201d remarks Prof. Urakami. He further adds, \u201cThis discovery will guide material selection for the development of functional photovoltaic devices in the near future.\u201d<\/em><\/p>\n\n\n\n

The research team is hopeful that their efforts will eventually have a positive environmental impact by contributing to the field of renewable energy generation. \u201cOur findings have the potential to further accelerate the spread of solar cells, one of the key technologies for environmental energy harvesting and a promising avenue towards a carbon neutral society<\/em>,\u201d concludes a hopeful Prof. Urakami.<\/p>\n\n\n\n

We hope that this study paves the way for further studies to harness the BVP effect and vastly improve the performance of solar cells, as well as enhance the design of sensitive photodetectors.<\/p>\n\n\n

Source<\/h5>\r\n\n\n\n

SHINSHU UNIVERSITY 2024<\/a><\/p>\n

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