The efficiency result was confirmed by the US National Renewable Energy Laboratory. The module was manufactured with 13.4%-efficient besterite cells designed with high film porosity and uniformity.
Scientists from Nanjing University of Posts and Telecommunications in China have manufactured a kesteriet (CZTSSE) Solar module prototype that can achieve a power conversion -efficiency of 10.1%.
The researchers said the result was certified by the National Renewable Energy Laboratory (NREL) of the US Department of Energy.
The new module is based on Cztsse solar cells with an efficiency of 13.4%. The world record for such cells is 14.6%, reached by the Chinese Academy of Sciences (CAS) in June 2024.
Kesteriet is one of the most promising candidates for the material for slightly absorbing for potential use in cheaper thin film solar cells. Kesterites include common elements such as copper, tin, zinc and selenium. In contrast to CIGS connections, no bottlenecks have been expected in the future. However, Kesteriet is still less efficient than CIGS in mass production.
The academics explained that the solution -based manufacturing process of thin film Cztsse Cellen Includes two critical steps: precautionary deposits and crystallization at high temperature. This apparently clear route hides a significant pitfall that fusion reactions with multiple deeds easily cause composition and electronic ownership fluctuations in the film, making a barrier for efficient improvement and industrialization of Cztsse -Zonnellellen.
“We have made a breakthrough in achieving crystallization of direct phase transformation based on the CU+ -SN4+ solution method, which pushes Cztsse solar cell efficiency to more than 13%,” the corresponding author of the research, Shaoying Wang, said PV -MagazineHowever, noticing that one of the biggest challenges of their work was to maintain the high efficiency at module level.
“Initiable, the efficiency of our first fabricated cztsse module was only 4.3%, with a staggering cell-to-to-module power conversion efficiency (CTMPCE) loss of 56.81%, which reveals a High truth is faryly fercess of High-lareea Equivalent to producing high-quality Large-Scale Absorber Films, “He explained. “We also started with an in -depth exploration of the large loss of cells to module.”
The characterization and analysis of the film morphology and element distribution during a different stage of the crystallization process created an important problem: in the early phase of the selenization, a dense crystalline layer already arises on the surface of the film, which acts as an invisible barrier of the film and seriously calls the later scale of the later scale of the later scale.
“This hinders grain growth in vertical directions and results in poor film uniformity and high surface line,” Wang said. “The non-uniform absorption film cannot support the production of efficient and large devices, taking into account the poor performance and the large CTM loss of our earlier modules.”
The group decided to change the microstructure of the predecessor film used for the perovskietabsorber and its porosity to regulate the rapid formation of a dense top layer in the early stage of selenization and to create more space for subsequent selenium (SE) PERMATION and more time for lateral growth growth.
The microstructure of the precursor film was closely linked to the composition of the precursor solution, which was based on Thiourea (TU), a reagent that dissects during thermal decomposition and releases from volatile gases from the film, increasing the film porosity.
“That is why we systematically regulate the ratio of TU to Metaal ions in the precursor solution and we investigate the film morphology,” Wang said. “The results were encouraging: after increasing the TU content, the precursor film became more porous and looser, making the formation of a looser top crystalline layer possible at an early stage of selenization, allowing more SE to penetrate more SE in the film bulk and offers more space for lateral grain growth and the flat file.”
The cell of 0.1 cm2 was built with a substrate made of soft drink lime glass (SLG) and coated with molybdenum (MO), a Cztse absorber, a cadmium sulfide (CDS) layer, a buffer layer made of zinc oxide (ZNO), an indium tinoxide (ITO) low and aluminum (Al) and nickel (NI) metal contacts.
“Based on the improved uniformity of the absorbent film, we have successfully achieved an average efficiency of 13.4% for single cells with a very low standard deviation and an efficiency of 8.91% for the solar module,” Wang emphasized. “But this was not the end. We had further adjusted the modul structure to reduce non-ideal contact and shunting caused by series resistance, resulting in a certified 10.1% efficiency and an opening area of 10.48 cm2 with a low CTMPCE of 25.3% and the lowest CTM loss) in open-circuit) and the lowest CTM-loss)” “
“This is not only the first solution solution module, but also a journey for understanding and tackling the underlying challenges with the manufacture of inorganic thin films through solution approach,” he concluded. “This work offers a clear and feasible technical route for solution processing of high-quality large-area inorganic connection Dunne film solar cells and modules.”
The new cell and panel technology was presented in the paper “Perwork-processed kesterite solar module with 10.1% certified efficiency“Which was recently published in Natural energy.
In April 2023, other researchers from Nanjing University of Posts and Telecommunication designed High crystalline quality of Cztsse Absorbers, with low defects.
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