Photovoltaic Materials Group

Solar cells has highly attracted great interest in order to solve the global warming and other environmental issues. Focusing on creating second and third generation solar cells with ultra-high energy conversion efficiency and low manufacturing cost, our main objectives are elucidating photoelectric conversion mechanism, developing new solar cell structure, and generating new solar cell materials.

Perovskite solar cells

Organo metal halide perovskites (ABX3, A = organic cation, B = Pb or Sn, X = halogen) are arising as a new generation of low cost and solution processable absorber materials for solar cells. Perovskite solar cells show superb photovoltaic performance due to high absorption coefficient and balanced charge transporting properties. The device structure of perovskite solar cells is diverse, such as DSC-type sensitized mesostructure and OPV-type planar structure. Our research on perovskite solar cell involves in:
(1) Film morphology control for improving efficiency and reproducibility;
(2) Design new materials for improving device performance and stability;
(3) Device engineering for record efficiency;
(4) Understanding the fundamental working principle of perovskite solar cells.


Latest News

New efficiency record claimed for perovskite solar cells

Recently, we have set a new benchmark for the power conversion efficiency of perovskite solar cells. In an independent public test center (AIST, Japan), a new world record efficiency of 19.2% was measured for a cell with aperture area > 1 cm2 under standard testing conditions. This was achieved through device structure optimization and new materials development.

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What we are doing

Film morphology control

Through film morphology control and device structure engineering, we have realized highly efficient and reproducible DSC-type perovskite solar cells, with the highest efficiency to 16.7%.

"Left: J-V curve of the best performing DSC-type perovskite solar cell; Right: scheme diagram of the DSC-type perovskite solar cells" Image

Left: J-V curve of the best performing DSC-type perovskite solar cell;
Right: scheme diagram of the DSC-type perovskite solar cells




New materials development

A concept of dopant-free hole transport material (HTM) was proposed for improving the humid stability of perovskite. By using a pristine TTF-1 as HTM, DSC-type perovskite solar cells show comparable efficiency but much higher stability to the standard spiro-OMeTAD based devices

"Left: chemical structure of TTF-1 and spiro-OMeTAD; Right: the long-term stability of TTF-1 and spiro-OMeTAD based DSC-type perovskite solar cells" Image

Left: chemical structure of TTF-1 and spiro-OMeTAD;
Right: the long-term stability of TTF-1 and spiro-OMeTAD based DSC-type perovskite solar cells




Interfacial engineering

A hybrid NiO-Al2O3 interfacial layer was developed for improving the performance of OPV-type planar structured perovskite solar cells. The incorporation of a thin and porous Al2O3 layer greatly decrease the interfacial charge recombination and improve the shunt resistance of solar cell devices.

"Left and middle: Scheme diagram and band energy alignment of the OPV-type perovskite solar cells with a NiO-Al2O3 hybrid interfacial layer; Right: the J-V curves of device with and without Al2O3 layer." Image

Left and middle: Scheme diagram and band energy alignment of the OPV-type perovskite solar cells with a NiO-Al2O3 hybrid interfacial layer; Right: the J-V curves of device with and without Al2O3 layer.




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Photovoltaic Materials Group
1-2-1 Sengen, Tsukuba, Ibaraki, 305-0047 JAPAN
National Institute for Materials Science (NIMS)
1-2-1 Sengen, Tsukuba, Ibaraki 305-0047, JAPAN
TEL.+81-(0)-29-859-2000
FAX.+81-(0)-29-859-2029