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Low Pressure Vapor-assisted Solution Process for Tunable Band Gap Pinhole-free Methylammonium Lead Halide Perovskite Films
Published on: September 8, 2017
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Structural distortion induced broad emission in vacancy-ordered halide triple perovskites
Maruthi Mala1, Tamilselvan Appadurai1, Aravind Kumar Chandiran1,2
1Department of Chemical Engineering, Indian Institute of Technology Madras, Adyar, Chennai, Tamil Nadu 600036, India. aravindkumar@iitm.ac.in.
Dalton Transactions (Cambridge, England : 2003)
|January 27, 2022
Summary
Introducing asymmetry in halide perovskites enhances light emission. This structural distortion improves photoluminescence and excited-state lifetimes, crucial for advanced light-emitting diodes.
Area of Science:
- Materials Science
- Solid-State Chemistry
- Optoelectronics
Background:
- Halide perovskites are key materials for tunable optical properties.
- Symmetry in their octahedral structures limits photoluminescence and excited-state lifetimes.
- Introducing asymmetry offers a pathway to enhance performance for applications like white light emitters.
Purpose of the Study:
- To systematically introduce asymmetry in vacancy-ordered halide triple perovskite materials (Cs3M2X9).
- To investigate the impact of this structural distortion on optical properties.
- To explore the potential for improved light emission and excited-state lifetimes.
Main Methods:
- Synthesized Cs3M2X9 perovskite materials with mixed trivalent sites (M = Bi3+, Sb3+; X = Cl-, Br-, I-).
- Employed Raman spectroscopy and Fourier-transform infrared (FT-far-IR) measurements to analyze structural distortion.
- Characterized the resulting optical properties, focusing on photoluminescence and excited-state dynamics.
Main Results:
- Successfully introduced structural asymmetry in Cs3M2X9 materials through site mixing.
- Observed enhanced self-trapped excitonic emission, characterized by broad and intense spectra covering the visible region.
- Demonstrated significant improvements in excited-state lifetimes due to the introduced distortion.
Conclusions:
- Structural distortion is an effective strategy to tune the optical properties of halide perovskites.
- The enhanced emission and lifetimes are promising for applications in efficient light-emitting diodes.
- This approach provides a new avenue for designing high-performance optoelectronic materials.
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