AUTHOR=Liao Xuan-Xiang , Zhang Yong , Sadjadi SeyedAbdolreza TITLE=Exploring the possibility of polycyclic aromatic hydrocarbons and fulleranes as the carrier of the 21 micron emission feature JOURNAL=Frontiers in Astronomy and Space Sciences VOLUME=11 YEAR=2024 URL=https://www.frontiersin.org/journals/astronomy-and-space-sciences/articles/10.3389/fspas.2024.1489982 DOI=10.3389/fspas.2024.1489982 ISSN=2296-987X