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Conceived by South Korean scientists, the cell was built with an electron transport layer made of tin oxide through a low-temperature process. The device reportedly achieved the highest energy conversion efficiency ever recorded for flexible quantum dot solar cells.
A group of South Korean researchers has developed a flexible quantum dot solar cell based on the all-inorganic cesium-lead iodide (CsPbI3) perovskite, also known as black perovskite. Cells constructed with quantum dots are known to exhibit high photoluminescence (PL) quantum yields, due to their high defect tolerance, and high open-circuit voltages.
Quantum dots are tiny semiconductor particles that can carry a charge and can be made from a variety of materials. They have long been investigated as possible materials for solar cells. Those based on perovskites have been especially attractive to researchers in the photovoltaic sector, which have already demonstrated efficiencies greater than 16%.
According to the Korean scientists, the advantage of CsPbI3 perovskite quantum dots lies in their ability to be easily deposited on any substrate with the desired nanoscale thickness using a layer-by-layer (LBL) method at room temperature. “This simple, low-temperature process facilitates the manufacturing of devices even on light and flexible polymer-based substrates,” they explained.
Another important feature of the cell is its electron transport layer (ETL), made of tin oxide (SnO2) processed at room temperature and intended to improve photovoltaic performance by controlling the energy level, while minimizing damage. to the polymeric substrate thanks to the low temperature process. “The energy level of SnO2 is controlled by doping gallium ions to reduce the energy level mismatch with the perovskite quantum dots,” the researchers explain.
The group constructed the cell with an indium tin oxide (ITO) substrate, the SnO2-based ETL, the CsPbI3-QD absorber, a Spiro-OMeTAD-based hole transport layer (HTL), and a gold metal contact. (Aw).
Tested under standard lighting conditions, the cell achieved a power conversion efficiency of f12.70%, which the scientists say is the highest recorded to date for all types of flexible quantum dot solar cells. Furthermore, the cell retained around 94% of its initial efficiency after 500 bending tests.
“CsPbI3 perovskite quantum dot films are expected to provide greater mechanical stability than bulk perovskite films due to their nanoscale grain boundaries and soft surface ligands, underscoring their potential as flexible device components,” They further explained.
The new solar cell was presented in the study “ Completely annealing-free flexible Perovskite quantum dot solar cells employing UV-sintered Ga-doped SnO2 electron transport layers. ” electron transport of Ga-doped and UV-sintered SnO2), published in npj flexible electronics . The research group was made up of scientists from the South Korean universities of Hanyang and Kookmin. |
