講演情報
[9p-N323-5]Photosensitive Properties of CsPbBr3 Nanocrystals under Bichromatic Photoexcitation of Above-bandgap and Sub-bandgap Photons
〇(DC)Hambalee Mahamu1, Soma Ueno1, Shigeo Asahi1, Takashi Kita1 (1.Kobe Univ.)
キーワード：
Perovskite、Solar Cells、Photon Upcoversion
We studied the intrinsic photosensitive properties of CsPbBr3 nanocrystals under sub-bandgap photoexcitation conditions, aiming to distinguish these properties from the two-step photon upconversion (TPU) phenomenon. Since we have observed photocurrent and photovoltage enhancement in CsPbBr1.5Cl1.5/PbS/CsPbBr3-based two-step photon upconversion solar cells (TPU-SCs), the study of photosensitive properties of CsPbBr3 on sub-bandgap photons enables us to draw a clear line between the intrinsic properties and the TPU. In addition, we found that the photocurrent and photovoltage of CsPbBr3 nanocrystal-based single-junction solar cells (SCs) can be enhanced by additional sub-bandgap photoexcitation at low temperatures, which is a useful feature to increase the efficiency of solar cells. However, with increasing temperature, such characteristics disappear due to phonon-assisted processes that dominate the optical process. The photosensitive characteristics, at low temperatures, might be useful for further understanding of the photophysical properties of perovskite nanocrystals. Furthermore, the characteristics can be considered as an influence of intermediate bands (IBs) since the concept of IBs explains the photocurrent and photovoltage efficiently.