KalimNews, Kalimpong, 26 May 2024 : In recent times, there have been numerous encouraging reports highlighting the achievements of young people from Kalimpong, Darjeeling, the Gorkhas of the plains, and surrounding areas. These young individuals have been excelling in various fields, bringing pride to their communities and inspiring others.
It’s the time when the Gorkha community is making significant progress in various fields, including scientific discoveries. Consequently, Dr. Kamal Bhujel, a resident of Dilaram Tea Estate, has pioneered a new process known as Negative Absorption in the Infrared region during his research. Dr. Kamal Bhujel attained his PhD degree from the Department of Physics at Mizoram University in 2023.
His research focused on Thin-film Perovskite solar cells, conducted primarily at the Solar Energy Research Lab at the Indian Institute of Technology-Dhanbad (IIT-Dhanbad) under the guidance of Professor Rajalingam Thangavel. During the fabrication of these solar cells, he engineered a thin film of Nickel oxide, with a thickness measured in nanometers, onto FTO (Fluorine Doped Tin Oxide).
In solar cell applications, it is essential to assess both the optical and electrical properties. To do so, measuring Absorption and Transmittance becomes mandatory. This involves directing a light wave (ranging from 200 to 3000nm) onto the sample and observing the degree of absorption and transmission of the incident wave. The outcome of these measurements yielded unexpectedly surprising results.
It was discovered that the quantity of transmitted wave exceeded that of the incident wave, causing the Absorption curve to exhibit negativity, hence termed ‘Negative Absorption.’ This phenomenon contradicts the ‘Law of Conservation of Energy,’ presenting an apparent impossibility. Notably, no prior reports of such a process in nickel oxide existed. A similar discovery was made by CV Raman and KS Krishnan in 1928, involving irradiation of a liquid with a monochromatic wave, yet research in this domain remains scarce.
Dr. Kamal Bhujel suggests that the precise mechanism underlying this process remains elusive. While this research furnishes compelling evidence for its existence, further rigorous investigations are indispensable to elucidate its origins.
Dr. Kamal Bhujel suggests that the precise mechanism underlying this process remains elusive. While this research furnishes compelling evidence for its existence, further rigorous investigations are indispensable to elucidate its origins.
Dr. Kamal proposes a tentative explanation: when infrared waves interact with the junction of FTO and nickel oxide, molecules in this region become excited and transform into energy, resulting in a transmittance exceeding 100%.
The recent discovery of negative absorption in the infrared (IR) region by Dr. Kamal Bhujel and his team holds significant potential for the development of new types of metamaterials and advanced applications in various fields.
This research was supported by Dipali Nayak, a PhD scholar from the Department of Physics at IIT-Dhanbad, along with MSc students Kiran Kumari Pal and Pritam Sardar. Prof. Suman Rai and Dr. Ningthoujam S. Singh assisted in the manuscript preparation, and Prof. Thangvel provided overall direction for the research.
Negative absorption in the IR region could pave the way for creating innovative metamaterials that manipulate light in unconventional ways, potentially leading to advancements in optoelectronics and sensing technologies. \
Additionally, this phenomenon could be particularly useful in the synthesis of solar cells designed for spacecraft, where harnessing infrared radiation is critical due to its abundance in space environments.
To ensure the robustness and recognition of such a groundbreaking discovery, it is essential that the research undergoes rigorous peer review and is published in a prestigious scientific journal. This process will validate the findings and facilitate further exploration and application of these novel materials in the scientific community.
Any new findings within the scientific community necessitate publication in a renowned, world-class journal, substantiated by rigorous peer review.
Despite initiating this research in 2020 and completing it by 2022, Dr. Kamal Bhujel faced a prolonged wait for publication. Initially rejected by the first journal due to perceived insufficiencies, his work underwent further scrutiny across seven subsequent submissions, each transferring to journals aligned with their respective fields.
Finally, on February 28, 2024, the manuscript found its home in Physica B: Condensed Matter, a journal within the Elsevier Group. Following a thorough revision process addressing reviewers’ comments, acceptance came swiftly on May 20, with online publication following on May 21. Dr. Bhujel expresses profound joy at the publication of his research, extending heartfelt gratitude to all supporters. He encourages fellow Gorkha researchers to persist in advancing their studies in a similar vein.