Reducing Nonradiative Recombination Losses in Tin-Based Perovskite LEDs Utilizing a Self-Assembled Monolayer.

Area of Science:

• Materials Science
• Optoelectronics
• Semiconductor Physics

Background:

• Tin-based perovskites offer a less-toxic alternative to lead-based materials for optoelectronic applications.
• Pure red tin-based perovskite LEDs (Sn-LEDs) exhibit lower efficiency than lead-based counterparts due to poor electron blocking at the PEDOT:PSS/perovskite interface.
• This interfacial issue causes nonradiative recombination, limiting overall device performance.

Purpose of the Study:

• To address the efficiency limitations in tin-based perovskite LEDs (Sn-LEDs).
• To investigate the use of a self-assembled monolayer (SAM) as a hole-selective layer in Sn-LEDs.
• To improve electron blocking and reduce interfacial recombination in Sn-LEDs.

Main Methods:

• Replacement of the conventional PEDOT:PSS hole-selective layer with a novel self-assembled monolayer (SAM), EADR03.
• Characterization of the EADR03 layer's function as both an electron-blocking and hole-injecting layer.
• Evaluation of the impact of the SAM on Sn-LED performance metrics, particularly external quantum efficiency.

Main Results:

• The study reports the first use of a SAM (EADR03) as a hole-selective layer in tin-based perovskite LEDs (Sn-LEDs).
• EADR03 effectively functions as both an electron-blocking and hole-injecting layer at the PEDOT:PSS/perovskite interface.
• A threefold enhancement in external quantum efficiency was achieved for the Sn-LEDs utilizing the EADR03 SAM.

Conclusions:

• The developed SAM, EADR03, significantly enhances the performance of tin-based perovskite LEDs by mitigating interfacial recombination.
• This work presents a promising strategy for advancing the efficiency and viability of tin-based perovskite optoelectronic devices.
• The findings pave the way for the development of more efficient and less-toxic red Sn-LEDs.