Temperature-dependent Mn²⁺ emission in codoped CsPb₂ (BrCl)₅ perovskite nanocrystals

Area of Science:

• Materials Science
• Nanotechnology
• Solid-State Physics

Background:

• Perovskite nanocrystals (NCs) are promising for optoelectronics.
• Understanding doping effects on NC optical properties is essential.

Purpose of the Study:

• To investigate the optical mechanisms of Mn2+ emission in Cu/Mn codoped CsPb2(BrCl)5 NCs.
• To explore the influence of temperature on Mn2+ emission characteristics.
• To evaluate the role of Cu2+ in enhancing energy transfer.

Main Methods:

• Facile two-step solution synthesis of codoped CsPb2(BrCl)5 NC films.
• Temperature-dependent photoluminescence spectroscopy (80-300 K).
• Analysis of Mn2+ emission peak shifts and linewidth broadening.

Main Results:

• Observed anomalous blueshift and broadening of Mn2+ emission with increasing temperature due to electron-optical-phonon coupling (average phonon energy ~50 meV).
• Determined activation energy of 79.32 meV.
• Demonstrated that Cu2+ introduction significantly enhances energy transfer (ET) from the CsPb2(BrCl)5 host to Mn2+, boosting Mn2+ emission intensity.

Conclusions:

• Cu2+ doping effectively promotes energy transfer in Mn-doped CsPb2(BrCl)5 NCs.
• Temperature-dependent optical properties are governed by strong electron-phonon coupling.
• Insights into the optical mechanisms are vital for developing advanced optoelectronic devices using these codoped NCs.