Interfacial-Bulk Synergistic Passivation for High-Performance Self-Powered CsPbBr₃ Quantum Dot Photodetectors

Area of Science:

• Materials Science
• Nanotechnology
• Optoelectronics

Background:

• Lead halide perovskite quantum dots (QDs) have excellent optoelectronic properties for photodetection.
• Performance and stability of QD films are limited by surface and bulk defects.

Purpose of the Study:

• To address defects in perovskite quantum dot films using a synergistic interfacial-bulk dual passivation strategy.
• To enhance the performance and stability of QD-based photodetectors.

Main Methods:

• Employed a hybrid active layer of CsPbBr3 QDs and poly(3-hexylthiophene) (P3HT) for bulk heterojunction optimization.
• Utilized a hybrid passivator (tributylphosphine oxide and calcium bromide) for interfacial defect passivation between the HTL and active layer.
• Engineered the interface between the hole transport layer (HTL) and the active layer.

Main Results:

• Achieved passivation of QD surface defects and improved film morphology.
• Mitigated nonradiative recombination by passivating interfacial defects.
• Developed a self-powered photodetector with ultralow dark current (2.01 × 10^-13 A).
• Demonstrated high responsivity (1.25 A/W), detectivity (9.85 × 10^14 Jones), and photosensitivity (6.25 × 10^7) under illumination.

Conclusions:

• The synergistic passivation strategy effectively manages defects in perovskite films.
• This approach provides a generalized paradigm for high-performance, self-powered perovskite optoelectronic devices.