image: The as-prepared Er(Ta1-xNbx)O4 (0≤x≤0.2) ceramics exhibit high emissivity (49%-93%) in the selective band (1.40-1.60 μm), high spectral efficiency (59.46%-62.12%) and excellent high-temperature stability at 1400 ℃. On the one hand, doping Nb5+ into the B-site changes the crystal local structure symmetry around Er3+, which promotes the f-f transition of Er3+ and enhances the selective emission performance. On the other hand, doping Nb5+ ions into the B-site can alter the band gap and oxygen vacancy concentration to suppress non-selective emissivity. Increasing the selective emissivity and reducing the non-selective emissivity is beneficial for improving the spectral efficiency of selective emitters. Hence, the selective emissivity and spectral efficiency of Er(Ta1-xNbx)O4 (0≤x≤0.2) can be effectively enhanced through compositional design, providing a new strategy for developing selective emitter materials for RTPV applications.
Credit: Journal of Advanced Ceramics, Tsinghua University Press
In recent decades, materials scientists have been searching for new emitter materials with excellent high-temperature stability and selective emission performance. A groundbreaking study by Professor Yang Fan's team at the Fujian Institute of Research on the Structure of Matter has revealed a new selective emitter material, Er(Ta1-xNbx)O4 (0≤x≤0.2), aimed at improving the energy conversion efficiency of radioisotope thermoelectric photovoltaic (RTPV) systems. This material exhibits excellent selective emissivity, spectral efficiency, and high-temperature stability, making it a promising candidate for the next generation of RTPV applications.
The team published their review in Journal of Advanced Ceramics on April 3, 2025.
“In this work, we prepared a series of rare earth tantalate ceramic Er(Ta1-xNbx)O4 (0≤x≤0.2) selective emitters, which have high PV convertible emission power of 7.07 W/cm2 and high spectral efficiency of 62.12%, significantly better than existing rare earth based ceramic selective emitters materials. In addition, they exhibit excellent high-temperature stability, maintaining their structural integrity and performance even at temperatures as high as 1400 ℃.” Professor Yang Fan from Fujian Institute of Research on the Structure of Matter said.
“The improvement in selective emissivity and spectral efficiency is attributed to the strategic doping of Nb5+ ions. This doping method not only changes the local crystal structure symmetry around Er3+ ions, but also promotes the f-f transition probability of Er3+ and increases its selective emission performance. At the same time, it also changes the bandgap width and oxygen vacancy concentration, which effectively suppresses non selective emissivity, which is a key factor in improving overall spectral efficiency.” Professor Yang Fan said.
“This innovative material not only solves the challenges faced by current RTPV systems, but also opens up new avenues for developing efficient, stable, and cost-effective energy conversion technologies. The successful synthesis and characterization of Er(Ta1-xNbx)O4 (0≤x≤0.2) marks an important step forward in the field of selective emitters, providing a promising solution for improving the energy conversion efficiency of RTPV systems.” Professor Yang Fan said.
This innovation not only provides new ideas for the design of selective emitter materials, but also proves that doping strategies are an effective way to improve the spectral efficiency of emitters. Meanwhile, the research team holds an optimistic attitude towards the application of their work. They believe that this method does not require complex manufacturing processes and can directly transition from basic research to practical engineering applications.
This research was supported by the National Natural Science Foundation of China (No. 52402093), the Self-deployment Project Research Programs of Haixi Institutes, Chinese Academy of Sciences (No. CXZX-2023-JQ07), the National Key Research and Development Program of China (No. 2022YFB3504302), the Young Elite Scientists Sponsorship Program by CAST (No. YESS20210336), and the XMIREM Autonomously Deployment Project (No. 2023GG03 and 2023CX01), Natural Science Foundation of Xiamen (No. 3502Z202472048).
About Author
Dr. Yang Fan(corresponding author), Chinese Academy of Sciences Fujian Institute of Research on the Structure of Matter, researcher, team leader, doctoral advisor, young top talent of Fujian Young Eagle Program, the most beautiful scientific and technological worker in Fujian Province, and external expert of the State Key Laboratory of Baiyunebo Rare Earth Resources Research and Comprehensive Utilization, Baotou Rare Earth Research Institute. Mainly engaged in research on the separation and recovery of rare earths and precious metals, as well as the development of new rare earth based ceramic materials. As of 2024, more than 40 papers have been published as first or corresponding authors in SCI journals such as Journal of the European Ceramic Society, Ceramics International. and more than 30 patents have been granted.
Dr. Chen Heng (corresponding author), Chinese Academy of Sciences Fujian Institute of Research on the Structure of Matter, associate researcher, master's supervisor, has been selected into the Young Talents Promotion Project of the Chinese Association of Science and Technology, Fujian Provincial High level Talents Class C, and Xiamen High level Talents Class C. Mainly engaged in the design, preparation, and performance research of high entropy ceramics, high-temperature/ultra-high temperature ceramics, nuclear special ceramics, and other materials. He has presided over six national/provincial and ministerial level projects, including the National Natural Science Foundation Youth Project and the Chinese Academy of Sciences Key Deployment Scientific Research Project (cultivation), published 30 sci papers and granted 6 patents. Served as a member of the Youth Committee of the Chinese Rare Earth Society, an expert in the Expert Database of the 7th Council of the Chinese Rare Earth Society, and a young editorial board member for journals such as Journal of Advanced Ceramics, Rare Earth, Modern Technology Ceramics, Extreme Materials, etc.
Ma Mengtong (first author), master's student, Jiangxi University of Science and Technology - Chinese Academy of Sciences Fujian Institute of Research on the Structure of Matter (joint cultivation), studied under Researcher Yang Fan and Associate Researcher Chen Heng. The research direction is the preparation and performance study of selective emitter materials for radioisotope thermoelectric systems.
About Journal of Advanced Ceramics
Journal of Advanced Ceramics (JAC) is an international academic journal that presents the state-of-the-art results of theoretical and experimental studies on the processing, structure, and properties of advanced ceramics and ceramic-based composites. JAC is Fully Open Access, monthly published by Tsinghua University Press, and exclusively available via SciOpen. JAC’s 2023 IF is 18.6, ranking in Top 1 (1/31, Q1) among all journals in “Materials Science, Ceramics” category, and its 2023 CiteScore is 21.0 (top 5%) in Scopus database. ResearchGate homepage: https://www.researchgate.net/journal/Journal-of-Advanced-Ceramics-2227-8508
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Journal
Journal of Advanced Ceramics
Article Title
A potential thermophotovoltaic emitter Er(Ta1−xNbx)O4 (0 ≤ x ≤ 0.2) with excellent selective emission performance
Article Publication Date
3-Apr-2025