{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,1]],"date-time":"2026-10-01T03:21:17Z","timestamp":1790824877053,"version":"4.1.0"},"reference-count":34,"publisher":"MDPI AG","issue":"6","license":[{"start":{"date-parts":[[2025,3,7]],"date-time":"2025-03-07T00:00:00Z","timestamp":1741305600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100006769","name":"Russian Science Foundation","doi-asserted-by":"publisher","award":["24-23-00339"],"award-info":[{"award-number":["24-23-00339"]}],"id":[{"id":"10.13039\/501100006769","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Materials"],"abstract":"<jats:p>Compounds of the general composition A2BIBIIIX6 with a double perovskite (elpasolite) structure are currently considered as an alternative to lead halide perovskites APbX3 in electronics and photovoltaics due to their greater compositional flexibility and low toxicity. One such alternative is the recently synthesized double perovskite Cs2AgNaBiBr6 and a number of various substituted compounds. The close values of the radii of silver and sodium cations make tuning the optoelectronic properties of the double perovskite via the substitution of Ag+ by Na+ promising if the formation of the substitution solid solution Cs2Ag1\u2212xNaxBiBr6 takes place. We explored different possible routes for the synthesis of this class of materials, including solid-phase or melt crystallization ampoule syntheses. Varying heating temperature and duration and using standard cooling processing or a quenching-like process, we demonstrate the instability of Cs2NaBiBr6 and Na-substituted compounds Cs2\u2212xNaxAgBiBr6 in the temperature range of 300\u2013650 \u00b0C. It is worth noting that the formation of Cs2Ag1\u2212xNaxBiBr6 solid solutions by a solid-phase method is more favorable.<\/jats:p>","DOI":"10.3390\/ma18061197","type":"journal-article","created":{"date-parts":[[2025,3,7]],"date-time":"2025-03-07T07:05:46Z","timestamp":1741331146000},"page":"1197","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":4,"title":["Ampoule Synthesis of Na-Doped Complex Bromide Cs2AgBiBr6 with Double Perovskite Structure"],"prefix":"10.3390","volume":"18","author":[{"given":"Nigina K.","family":"Nosirova","sequence":"first","affiliation":[{"name":"Department of Material Science, Lomonosov Moscow State University, 119991 Moscow, Russia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5704-5109","authenticated-orcid":false,"given":"Rustam K.","family":"Kamilov","sequence":"additional","affiliation":[{"name":"Department of Material Science, Lomonosov Moscow State University, 119991 Moscow, Russia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Maqsudjon M.","family":"Ibrohimov","sequence":"additional","affiliation":[{"name":"Department of Material Science, Lomonosov Moscow State University, 119991 Moscow, Russia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Leonid S.","family":"Lepnev","sequence":"additional","affiliation":[{"name":"P.N. Lebedev Physical Institute of the Russian Academy of Sciences, 119991 Moscow, Russia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mikhail O.","family":"Astafurov","sequence":"additional","affiliation":[{"name":"Department of Material Science, Lomonosov Moscow State University, 119991 Moscow, Russia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Alexander V.","family":"Knotko","sequence":"additional","affiliation":[{"name":"Department of Material Science, Lomonosov Moscow State University, 119991 Moscow, Russia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6102-9024","authenticated-orcid":false,"given":"Anastasia V.","family":"Grigorieva","sequence":"additional","affiliation":[{"name":"Department of Material Science, Lomonosov Moscow State University, 119991 Moscow, Russia"},{"name":"Department of Chemistry, Lomonosov Moscow State University, 119991 Moscow, Russia"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,3,7]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"4874","DOI":"10.1039\/D2SC00574C","article-title":"Synthesis of double perovskite and quadruple perovskite nanocrystals through post-synthetic transformation reactions","volume":"13","author":"Yang","year":"2022","journal-title":"Chem. Sci."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"2201112","DOI":"10.1002\/solr.202201112","article-title":"Challenges and Progress in Lead-Free Halide Double Perovskite Solar Cells","volume":"7","author":"Ji","year":"2023","journal-title":"Solar RRL"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"3742","DOI":"10.1039\/D2MA00071G","article-title":"Recent developments of lead-free halide double perovskites: A new superstar in the optoelectronic field","volume":"3","author":"Ghosh","year":"2022","journal-title":"Mater. Adv."},{"key":"ref_4","doi-asserted-by":"crossref","unstructured":"Obada, D.O., Akinpelu, S.B., Abolade, S.A., Okafor, E., Ukpong, A.M., Kumar, S.R., and Akande, A. (2024). Lead-Free Double Perovskites: A Review of the Structural, Optoelectronic, Mechanical, and Thermoelectric Properties Derived from First-Principles Calculations, and Materials Design Applicable for Pedagogical Purposes. Crystals, 14.","DOI":"10.3390\/cryst14010086"},{"key":"ref_5","first-page":"12856","article-title":"Lead-Free Halide Perovskite Cs2AgBiBr6\/Bismuthene Composites for Improved CH4 Production in Photocatalytic CO2 Reduction","volume":"5","author":"Zhang","year":"2022","journal-title":"ACS Appl. Energy Mater."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"2105898","DOI":"10.1002\/adfm.202105898","article-title":"Lead-Free Double Perovskite Cs2AgBiBr6: Fundamentals, Applications, and Perspectives","volume":"31","author":"Lei","year":"2021","journal-title":"Adv. Funct. Mater."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"2683","DOI":"10.1021\/acs.chemmater.2c03505","article-title":"Advances in the Synthesis of Halide Perovskite Single Crystals for Optoelectronic Applications","volume":"35","author":"Yan","year":"2023","journal-title":"Chem. Mater."},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Kamilov, R.K., Yuldoshev, J.Z., Knotko, A.V., and Grigorieva, A.V. (2023). Phase Equilibria in Ternary System CsBr-AgBr-InBr3. Materials, 16.","DOI":"10.3390\/ma16020559"},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Kamilov, R.K., Yuldoshev, J.Z., Knotko, A.V., and Grigorieva, A.V. (2023). In Search of a Double Perovskite in the Phase Triangle of Bromides CsBr-CuBr-InBr3. Materials, 16.","DOI":"10.3390\/ma16103744"},{"key":"ref_10","first-page":"1456","article-title":"Melt synthesis of halide perovskites: Structural control and applications","volume":"23","author":"Lee","year":"2023","journal-title":"Cryst. Growth Des."},{"key":"ref_11","first-page":"2201567","article-title":"High-frequency heating for perovskite synthesis: A breakthrough in rapid production","volume":"11","author":"Tan","year":"2024","journal-title":"Adv. Mater. Interfaces"},{"key":"ref_12","first-page":"13456","article-title":"Advances in Lead-Free Perovskite Materials","volume":"9","author":"Smith","year":"2021","journal-title":"J. Mater. Chem. A"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"3397","DOI":"10.1038\/s41467-022-31016-w","article-title":"Hydrogenated Cs2AgBiBr6 for significantly improved efficiency of lead-free inorganic double perovskite solar cell","volume":"13","author":"Zhang","year":"2022","journal-title":"Nat. Commun."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"2005521","DOI":"10.1002\/adfm.202005521","article-title":"Near-Infrared Light-Responsive Cu-Doped Cs2AgBiBr6","volume":"30","author":"Ji","year":"2020","journal-title":"Adv. Funct. Mater."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"21780","DOI":"10.1039\/D0TA07145E","article-title":"Bandgap lowering in mixed alloys of Cs2Ag(SbxBi1\u2212x)Br6 double perovskite thin films","volume":"8","author":"Li","year":"2020","journal-title":"J. Mater. Chem. A"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"19972","DOI":"10.1039\/C7TA06816F","article-title":"Highly stable, phase pure Cs2AgBiBr6 double perovskite thin films for optoelectronic applications","volume":"5","author":"Greul","year":"2017","journal-title":"J. Mater. Chem. A"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"5813","DOI":"10.1039\/D2MA00179A","article-title":"Photoinduced degradation of thermally stable Cs2AgBiBr6 double perovskites by micro-Raman studies","volume":"3","author":"Dakshinamurthy","year":"2022","journal-title":"Mater. Adv."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"1449","DOI":"10.1007\/s11082-024-07387-3","article-title":"Investigation of the properties of lead-free Cs2NaBiX6 (X\u2009=\u2009I and Br) double perovskites using density functional theory (DFT)","volume":"56","author":"Babaei","year":"2024","journal-title":"Opt. Quantum Electron."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"24","DOI":"10.1016\/j.scriptamat.2020.03.040","article-title":"Advanced Raman spectroscopy of Cs2AgBiBr6 double perovskites and identification of Cs3Bi2Br9 secondary phases","volume":"184","author":"Pistor","year":"2020","journal-title":"Scr. Mater."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"115288","DOI":"10.1016\/j.ssc.2023.115288","article-title":"Enhanced optical properties of lead-free double perovskite Cs2AgBiBr6 nanocrystals by doping of Na ions","volume":"373\u2013374","author":"Li","year":"2023","journal-title":"Solid State Commun."},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"Wu, Y., Meng, Y., Hu, Q., Shen, S., Zhang, C., Bian, A., and Dai, J. (2024). A-Site Ion Doping in Cs2AgBiBr6 Double Perovskite Films for Improved Optical and Photodetector Performance. Crystals, 14.","DOI":"10.3390\/cryst14121068"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"1371","DOI":"10.1016\/j.scib.2020.04.018","article-title":"Reducing current fluctuation of Cs3Bi2Br9 perovskite photodetectors for diffuse reflection imaging with wide dynamic range","volume":"65","author":"Zhong","year":"2020","journal-title":"Sci. Bull."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"12863","DOI":"10.1039\/D2TC01762H","article-title":"Structure modulation for bandgap engineered vacancy-ordered Cs3Bi2Br9 perovskite structures through copper alloying","volume":"10","author":"Elattar","year":"2022","journal-title":"J. Mater. Chem. C"},{"key":"ref_24","doi-asserted-by":"crossref","unstructured":"Aragon, A.G., Wiggins, T.E., Ma, X., and Geyer, S.M. (2023). Lead-free Cs3Bi2Br9 and Cs3Bi2\u2212xSbxBr9 nanocrystals as photocatalysts with enhanced activity for the degradation of rhodamine in aqueous environments. J. Photochem. Photobiol. A Chem., 436.","DOI":"10.1016\/j.jphotochem.2022.114391"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"490","DOI":"10.1002\/pssb.201451268","article-title":"Band-gap and phonon distribution in alkali halides","volume":"252","author":"Messaoudi","year":"2014","journal-title":"Phys. Status Solidi B"},{"key":"ref_26","unstructured":"Mitzi, D.B. (2020). Lead-Free Halide Perovskites: Properties and Applications, Springer."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"3688","DOI":"10.1039\/C9TC00400A","article-title":"Controlled synthesis and photostability of blue emitting Cs3Bi2Br9 perovskite nanocrystals by employing weak polar solvents at room temperature","volume":"7","author":"Gao","year":"2019","journal-title":"J. Mater. Chem. C"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"2100593","DOI":"10.1002\/pssb.202100593","article-title":"Growth and Optical Properties of Lead-Free Cs3Bi2Br9 Perovskite Microplatelets","volume":"259","author":"Deng","year":"2022","journal-title":"Phys. Status Solidi B"},{"key":"ref_29","first-page":"4452","article-title":"Cs2NaBiBr6: Optical and electronic properties of a lead-free double perovskite","volume":"5","author":"Saparov","year":"2017","journal-title":"J. Mater. Chem. C"},{"key":"ref_30","unstructured":"Becker, T., and Stolarczyk, J.K. (2021). Halide Perovskites: Photovoltaics, Light Emission, and Beyond, Wiley."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"299","DOI":"10.1021\/acsenergylett.8b02090","article-title":"Structural and Optical Properties of Cs2AgBiBr6 Double Perovskite","volume":"4","author":"Schade","year":"2019","journal-title":"ACS Energy Lett."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"3122","DOI":"10.1039\/D3CC00468F","article-title":"Crystal structure engineering of metal halide perovskites for photocatalytic organic synthesis","volume":"59","author":"Wang","year":"2023","journal-title":"Chem. Commun."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"3369","DOI":"10.1039\/C8TC05480K","article-title":"Lead-free double halide perovskite Cs3BiBr6 with well-defined crystal structure and high thermal stability for optoelectronics","volume":"7","author":"Tang","year":"2019","journal-title":"J. Mater. Chem. C"},{"key":"ref_34","doi-asserted-by":"crossref","unstructured":"Cao, F., Li, Z., Liu, X., Shi, Z., and Fang, X. (2022). Air Induced Formation of Cs3Bi2Br9\/Cs3BiBr6 Bulk Heterojunction and Its Dual-band Photodetection Abilities for Light Communication. Adv. Funct. Mater., 32.","DOI":"10.1002\/adfm.202206151"}],"container-title":["Materials"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1996-1944\/18\/6\/1197\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,9]],"date-time":"2025-10-09T16:48:59Z","timestamp":1760028539000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1996-1944\/18\/6\/1197"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,3,7]]},"references-count":34,"journal-issue":{"issue":"6","published-online":{"date-parts":[[2025,3]]}},"alternative-id":["ma18061197"],"URL":"https:\/\/doi.org\/10.3390\/ma18061197","relation":{},"ISSN":["1996-1944"],"issn-type":[{"value":"1996-1944","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,3,7]]}}}