Room-Temperature Synthesis and Photodetector Performance of All-Inorganic Lead-Free Cs 3 Bi 2 X 9 ( X = Cl, Br, I) Perovskite Nanocrystals
Year: 2025
Type: article
Abstract: High Resolution Image Download MS PowerPoint Slide All-inorganic halide perovskites have gained significant interest as environmentally friendly alternatives to Pb-based perovskites for optoelectronic applications. Here, we report the preparation of Pb-free inorganic Cs 3 Bi 2 X 9 ( X = Br, I, Cl) perovskite using a simple room-temperature antisolvent recrystallization method on soda-lime glass substrates. We thoroughly analyzed and compared the structural, optical, and morphological properties of these films. X-ray diffraction analysis revealed that the Cs 3 Bi 2 Cl 9 perovskite has the largest crystallite size (51 nm) compared to the Cs 3 Bi 2 Br 9 and Cs 3 Bi 2 I 9 perovskites. The perovskite films demonstrated enhanced crystallinity and exhibited hexagonal and orthorhombic phases with distinct space groups. Raman spectroscopy confirmed the successful formation of the Cs 3 Bi 2 X 9 phase. Field emission scanning electron microscopy analysis showed that Cs 3 Bi 2 X 9 exhibited irregular morphologies with noticeable voids across all samples. The surfaces were predominantly covered with uneven, spherical-like granules. The surface morphology displays dense packing with evident porosity and particle sizes ranging from submicrons to a few micrometers. The elemental analysis of the Cs 3 Bi 2 X 9 perovskite revealed the formation of nearly stoichiometric films. The light absorption edge of Cs 3 Bi 2 X 9 varied from 1.8 to 3.2 eV, depending on the halide composition. The formation of Cs 3 Bi 2 X 9 perovskites was confirmed using X-ray photoelectron spectroscopy analysis. Finally, we fabricated photodetectors based on Cs 3 Bi 2 X 9 . Among these, the Cs 3 Bi 2 Cl 9 perovskite-based photodetector exhibited superior performance, with a detectivity of 29.6 × 10 8 Jones, photoresponsivity of 1.14 mA/W, a fast rise time of 0.21 s, a decay time of 0.35 ms, and an internal quantum efficiency of 2.45 × 10 –1 %. These findings demonstrate the potential of Cs 3 Bi 2 Cl 9 perovskite-based photodetectors as promising candidates for next-generation, lead-free photodetector devices.
Language: English
Subfield: Electrical and Electronic Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $4,500
Funders: Ministry of New and Renewable Energy India, Council of Scientific and Industrial Research, India, University Grants Commission, Khalifa University of Science, Technology and Research, Savitribai Phule Pune University, Chhatrapati Shahu Maharaj Research Training and Human Development Institute
OpenAlex ID: W4415454747