Quantum Tunneling Effect in CsPbBr₃ Multiple Quantum Wells

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Two-dimensional (2D) lead halide perovskites (LHPs) exhibit unique optoelectronic properties due to strong quantum confinement.
• Efficient charge transport is crucial for optoelectronic device performance.

Purpose of the Study:

• Investigate charge carrier dynamics at the interface of CsPbBr3 multiple quantum wells (MQWs) and charge transporting layers.
• Decipher the mechanism of charge carrier extraction from MQWs.
• Understand the impact of barrier thickness on quantum tunneling and device performance.

Main Methods:

• Fabrication of CsPbBr3 MQWs with varying barrier (2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline - BCP) thickness.
• Steady-state and time-resolved photoluminescence spectroscopy.
• Femtosecond transient absorption experiments.
• Fabrication and characterization of quantum well (QW) photodetector devices.

Main Results:

• Charge carrier extraction from MQWs to TiO2 and Spiro-OMeTAD occurs via quantum tunneling.
• Carrier extraction efficiency is dependent on the BCP barrier thickness.
• Quantum tunneling mechanism was confirmed by spectroscopic techniques.

Conclusions:

• Quantum tunneling is an effective mechanism for charge carrier extraction in 2D LHP MQWs.
• Tailoring barrier thickness allows control over carrier extraction and device performance.
• This study offers insights into optimizing carrier extraction in quantum-confined systems.