Southeast University makes new progress in quantum efficiency research of van der Waals light-emitting diodes

Recently, Professor Ni Zhenhua from the School of Electronic Science and Engineering at Southeast University, Professor Lv Junpeng from the School of Physics, Professor Liu Hongwei from the School of Physical Science and Technology at Nanjing Normal University, and Professor Zhou Peng from the School of Microelectronics at Fudan University collaborated to propose a van der Waals light-emitting diode based on two-dimensional perovskite and combined with low-temperature van der Waals transfer technology, achieving a quantum efficiency of over 10% at room temperature. The related results were published in Science Advances under the title "Van der Waals integrated single functional light emitting diodes exceeding 10% quantum efficiency at room temperature".

At present, the main bottleneck in the development of optoelectronic integrated chips is the lack of high-performance on-chip light sources. Among numerous material systems, two-dimensional semiconductor materials have become an ideal material for building new generation optoelectronic systems and breaking through the bottleneck of high-performance on-chip light sources due to their excellent optoelectronic properties and integration advantages. Although significant progress has been made in two-dimensional semiconductor based light-emitting diode devices at present, their luminous efficiency at room temperature and high injection state is generally low, which limits their practical application in optoelectronic chips.

This study utilizes the characteristics of two-dimensional semiconductor materials with multiple quantum wells and combines them with low-temperature van der Waals transfer technology to achieve on-chip integrated high-efficiency light-emitting diodes. By utilizing the advantages of the two-dimensional perovskite multi quantum well structure and high fluorescence quantum yield, combined with the low potential barrier height of the graphene/two-dimensional perovskite interface, an external quantum efficiency of over 10% at room temperature has been achieved through efficient carrier tunneling recombination process, which is the highest level of current van der Waals light-emitting diodes. This scheme has universality and can be extended to other layered two-dimensional materials. This achievement lays a solid foundation for the future development of large-area, high-efficiency, high brightness, and on-chip integrated two-dimensional semiconductor light-emitting devices.

Ni Zhenhua, Lv Junpeng, Liu Hongwei, and Zhou Peng are the co corresponding authors of this article. Hu Zhenliang, a postdoctoral fellow at the School of Physics, Southeast University, and Fu Qiang, a doctoral student, are co first authors of this article. This work is supported by projects such as the National Key Research and Development Program, the National Natural Science Foundation of China, and the Jiangsu Provincial Natural Science Foundation.

Source: Opticsky