Development of Novel Perovskite Quantum Dot Solar Cell with Excellent Performance and Stability
작성자. Public Relations Team
Dr. Younghoon Kim's research team at DGIST has developed a perovskite quantum dot solar cell with phenethylammonium ligands that are moisture-resistant.
With its excellent electroluminescent properties, a lot of applications are expected(built-in solar power generation systems for buildings, Li-Fi, etc.).
▲(From left) Corresponding authors, Dr. Younghoon Kim, DGIST;
Professor Min Jae Ko, Hanyang University; and the lead author Jigeon Kim, DGIST
On July 14(Tuesday), Daegu Gyeongbuk Institute of Science and Technology (DGIST) announced that the research team of Dr. Younghoon Kim at the Division of Energy Technology has developed a technology to enhance the performance and stability of perovskite quantum dot solar cells. The technology is expected to significantly affect the development and commercialization of optical technologies, such as built-in solar power generation systems for buildings, multifunctional photovoltaic devices, and Li-Fi1, as it results in excellent electroluminescent properties.
Recently, with the increasing interest in solar cells including renewable energy technology, studies regarding solar cells using quantum dots have been actively conducted. Quantum dots have an excellent light absorption ability as well as an ability to absorb a wide range of light, rendering them the core material for next-generation solar cells. In particular, perovskite quantum dot solar cells, which have the highest efficiency among quantum dot solar cells, are gaining attention as multifunctional solar cells since they can convert light into electrical energy and vice versa.
Organic ligands with a long hydrocarbon chain are used to synthesize good perovskite quantum dots. The ligands are adsorbed on the surface of small perovskite quantum dots as small as 10 nanometers(nm)2, allowing them to be dispersed in various nonpolar solvent3. These quantum dots are well arranged on a substrate to produce a quantum dot solar cell. Because the ligands with a long chain adsorbed on the surface of the quantum dots render it difficult to transfer charges between the quantum dots, leading to the degradation of the performance of the solar cell, they must be replaced with ligands with a short hydrocarbon chain.
The performance of the device can be improved using ligands with a short hydrocarbon chain, referred to as “formamidinium”. However, the stability is significantly degraded by moisture in the air, owing to the hydrophilic nature of formamidinium ligands.
Through various experiments, Dr. Kim’s research team at the DGIST focused on the hydrophobicity of benzene group-based phenethylammonium(PEA) chain for application as a substrate to water molecules and the chain was stably adsorbed them onto the surface of perovskite quantum dots. The team improved the photoelectric conversion efficiency to 14.1% and further confirmed the stability, which enabled a high photoelectric conversion efficiency exceeding 90% to be maintained at a relative humidity of 20% to 25%, identical to the actual external environment, for approximately 15 days.
“For approximately 15 days, the performance and stability of the perovskite quantum dot solar were maintained on daily condition by introducing hydrophobic ligands with a short hydrocarbon chain.” And he also added “We can introduce a new paradigm for the both development and commercialization of next-generation quantum dot solar cells.”
The research was conducted in collaboration with Professor Min Jae Ko’s research team at the Department of Chemical Engineering, Hanyang University. Jigeon Kim, a commissioned researcher at the Division of Energy Technology of DGIST, and also a Ph.D. candidate student in Department of Chemical Engineering at Hanyang University, participated in the research as one of the lead authors. In addition, the research was published in the online edition of the internationally reputed scientific journal, Nano Energy.
--- 1Light Fidelity (Li-Fi): A wireless communication technology that utilizes light to realize fast communication speeds. It transmits data approximately 100 times faster than Wi-Fi (100 Mb/s). 2Nanometer (nm): A nanometer (nm) is 1 billionth of a meter (m). 3Nonpolar solvent: A solvent having a nonpolar molecule or similar, e.g., benzene, hexane, and toluene.
--- For more information, contact:
Younghoon Kim, Senior Researcher
Division of Energy Technology,
Daegu Gyeongbuk Institute of Science and Technology (DGIST)