The development of thin silicon solar cells has been facilitated by researchers ‘ discovery of a method to convert golden into a strong bandgap semiconductor.
Researchers at the University of California, Irvine have developed thin silicon solar cells that may aid in the development of the energy-converting systems in a variety of applications, including onboard aircraft and system charging, by enabling the creation of a novel way for light and matter to communicate.
The research, which was recently featured in a report just published as the cover account for the book ACS Nano, relies on the UC Irvine researchers ‘ switch from an direct to a strong bandgap silicon through its interaction with light.
The UC Irvine staff worked with researchers from Tel Aviv University and Kazan Federal University in Russia to create a novel method for heating the light more than altering the fabric itself. They restricted photons to sub-3-nanometer asperities close to the large semiconductor, creating a novel interaction pathway between light and matter by expanding speed. By “decorating” the golden area, the researchers said, they achieved a raise in light diffusion by orders of magnitude, along with a substantial increase in machine performance.
” Electrons move from the valence band to the conduction band” in semiconductors with a direct band gap. This process requires only a change in energy, it’s an efficient transfer”, noted lead author Dmitry Fishman, UC Irvine adjunct professor of chemistry. An additional component, such as a phonon, is required to give the electron the momentum required for the transition to occur in indirect bandgap materials like silicon. Silicon’s optical properties are inherently weak because a photon, phonon, and electron can interact at the same time and place at a low level.
He claimed that silicon’s poor optical properties as an indirect bandgap semiconductor hinder the development of optoelectronics in general and solar energy conversion. This is a disadvantage given that silicon is the second-most abundant element in the Earth’s crust and the foundation of the world’s computer and electronics industries.
” Photons carry energy but almost no momentum, but if we change this narrative explained in textbooks and somehow give photons momentum, we can excite electrons without needing additional particles”, said co-author Eric Potma, UC Irvine professor of chemistry. ” This reduces the interaction to just two particles, a photon and an electron, similar to what occurs in direct bandgap semiconductors, and increases light absorption by a factor of 10, 000, completely transforming light-matter interaction without changing the chemistry of the material itself”.
Co-author Ara Apkarian, UC Irvine Distinguished Professor emeritus of chemistry, said:” This phenomenon fundamentally changes how light interacts with matter. Traditionally, textbooks teach us about so-called vertical optical transitions, where a material absorbs light with the photon changing only the electron’s energy state. However, momentum-enhanced photons can change both the energy and momentum states of electrons, unlocking new transition pathways we had n’t considered before. Figuratively speaking, we can’ tilt the textbook,’ as these photons enable diagonal transitions. This dramatically impacts a material’s ability to absorb or emit light”.
According to the researchers, the development creates an opportunity to exploit recent advances in semiconductor fabrication techniques at the sub-1.5-nanometer scale, which has the potential to affect photo-sensing and light-energy conversion technologies.
” With the escalating effects of climate change, switching from fossil fuels to renewable energy is more urgent than ever.” Solar energy is key in this transition, yet the commercial solar cells we rely on are falling short”, Potma said. Because silicon ca n’t absorb light, these cells need thick layers, or almost 200 micrometers of pure crystalline material, to capture sunlight effectively. Due to increased charge carrier recombination, this not only raises production costs but also reduces efficiency. The thin-film solar cells that have been developed as a result of our research are widely accepted as the answer to these problems.
Other co-authors on this study included UC Irvine’s Jovan Merham and Aleksey Noskov, as well as Tel Aviv University investigators Liat Katrivas and Alexander Kotlyar, and Kazan Federal University researchers Elina Battalova and Sergey Kharintsev. The Chan Zuckerberg Initiative provided funding for the project.
