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Tetraoctylammonium Bromide Interlayer between NiLiO and Perovskite for Light-Emitting Diodes
Van-Khoe Vo1, Sung-Hoon Bae1, Thi Huong Thao Dang1
1School of Materials Science and Engineering, Kyungpook National University, Daegu 41566, Republic of Korea.
ACS Applied Materials & Interfaces
|November 12, 2024
Summary
Adding tetraoctylammonium bromide (TOABr) to perovskite thin films significantly enhances light-emitting diode (LED) performance. This interfacial modification reduces defects, boosting luminance and external quantum efficiency in vacuum-thermal-evaporated perovskite LEDs.
Area of Science:
- Materials Science
- Optoelectronics
- Nanotechnology
Background:
- Physical vapor deposition (PVD) is scalable for fabricating light-emitting diodes (LEDs).
- PVD-fabricated LEDs show lower performance than solution-processed ones due to high defect densities.
- Cesium lead bromide (CsPbBr3) is a key perovskite material for LEDs.
Purpose of the Study:
- To reduce nonradiative recombination and trap densities in CsPbBr3 perovskite films.
- To enhance the performance of perovskite LEDs fabricated via PVD.
- To investigate the effect of tetraoctylammonium bromide (TOABr) as an interfacial modifier.
Main Methods:
- Fabrication of perovskite thin films using physical vapor deposition.
- Introduction of a tetraoctylammonium bromide (TOABr) interfacial layer.
- Characterization of perovskite films and device performance, including photoluminescence and electrical measurements.
Main Results:
- TOABr addition slightly increased perovskite film crystallinity and preferred orientation.
- Photoluminescence dramatically increased with TOABr modification.
- Perovskite LEDs with TOABr showed a lower turn-on voltage (3 V), higher maximum luminance (11,133 cd m⁻²), and improved external quantum efficiency (1.24%) compared to pristine devices (0.015%).
Conclusions:
- TOABr effectively passivates defects and improves charge balance in perovskite films.
- The interfacial modification strategy enhances the performance of vacuum-thermal-evaporated perovskite LEDs.
- This approach offers a pathway for fabricating efficient perovskite LEDs using PVD techniques.
