1. Citric Acid Modulated Growth of Oriented Lead Perovskite Crystals for Efficient Solar Cells.
- Author
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Guo, Yunlong, Sato, Wataru, Shoyama, Kazutaka, Halim, Henry, Itabashi, Yuki, Shang, Rui, and Nakamura, Eiichi
- Subjects
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CITRIC acid , *SOLAR cells , *PEROVSKITE , *CRYSTALS , *HYSTERESIS - Abstract
Solar cells made of lead perovskite crystals have attracted much attention for their high performance, but far less attention as a subject of crystal engineering. Here, we report that citric acid (CA) and chloride anion, working together, modulate crystal growth of CH3NH3PbI3, producing sub-mm-sized cuboid crystalsa morphology more suitable for close packing in a thin film than the commonly observed elongated dodecahedral morphology. By using a 15 wt % CA-doped precursor solution, we formed a single layer of large, flat, and oriented cuboid crystals with minimum crystal domain boundaries and maximum contact with neighboring layers, and fabricated an archetypal inverted-structured device of 4 mm2 area, which showed, reproducibly and with little hysteresis, 16.75% power conversion efficiency (PCE), 26% higher than the PCE obtained for a polycrystalline film made without CA doping. Under weaker irradiation of a 1 cm2 device, the PCE improved from 14.52% (one sun) to 20.4% (0.087 suns). Under illumination with white light emitting diode, a 10 wt % CA-doped device showed PCE of 28.1%, suggesting an advantage of PVK-SCs for indoor applications. Further studies on crystal growth modulation will be beneficial for manufacturing efficient and stable lead perovskite solar cells. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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