講演情報
[22a-C601-2]All-inorganic CsPbI3-xBrx perovskite for indoor photovoltaics
〇Zhanglin Guo1, Tsutomu Miyasaka2 (1.Kyushu Univ., 2.Toin Univ. Yokohama)
キーワード：
perovskite solar cells、all-inorganic、indoor photovoltaics
Halide perovskite indoor photovoltaics are attracting increasing attention due to their tunable bandgap and defect-tolerance properties. Among various compositional perovskites, CsPbI3-xBrx are the most suitable indoor light absorbers because their bandgap (1.7-2.3 eV) perfectly matches the indoor light spectra. However, the low Voc of the cells is the main challenge for developing highly efficient CsPbI3-xBrx indoor photovoltaics.
This report introduces the techniques for improving the Voc and efficiency of CsPbI3-xBrx photovoltaic cells. In the first part, an ultra-thin but efficient amorphous SnOx electron transport layer prepared by simply aging the SnCl2 solution is introduced. With several positive effects, the average Voc of CsPbI2Br solar cells is promoted to over 1.40 V, reducing the energy loss to less than 0.50 eV, which is realized for the first time. In the second part, a new polymer was developed as a dopant-free hole transport material for CsPbI2Br solar cells. It not only further enhances the efficiency of CsPbI2Br solar cells to over 17.36%, but also generates a high efficiency of 34.20% under weak indoor light (200 lux) with an amazingly high Voc of 1.14 V. In the third part, a perovskite surface treatment engineering is developed to passivate the perovskite surface iodine vacancy defect, which works universally to promote the Voc of various CsPbI3-xBrx cells to over 90% of their theoretical limits. Moreover, the Voc under 200 lux indoor light is as high as 1.17 V and the efficiency is over 30%. More importantly, this report also analyses the issues in the research on perovskite indoor photovoltaics. As an example, it is found that in some published papers the photocurrent is over-estimated, resulting in inaccurate efficiency value. Thus, a standard photovoltaic performance characterization procedure is necessary to advance the development of indoor photovoltaics.
This report introduces the techniques for improving the Voc and efficiency of CsPbI3-xBrx photovoltaic cells. In the first part, an ultra-thin but efficient amorphous SnOx electron transport layer prepared by simply aging the SnCl2 solution is introduced. With several positive effects, the average Voc of CsPbI2Br solar cells is promoted to over 1.40 V, reducing the energy loss to less than 0.50 eV, which is realized for the first time. In the second part, a new polymer was developed as a dopant-free hole transport material for CsPbI2Br solar cells. It not only further enhances the efficiency of CsPbI2Br solar cells to over 17.36%, but also generates a high efficiency of 34.20% under weak indoor light (200 lux) with an amazingly high Voc of 1.14 V. In the third part, a perovskite surface treatment engineering is developed to passivate the perovskite surface iodine vacancy defect, which works universally to promote the Voc of various CsPbI3-xBrx cells to over 90% of their theoretical limits. Moreover, the Voc under 200 lux indoor light is as high as 1.17 V and the efficiency is over 30%. More importantly, this report also analyses the issues in the research on perovskite indoor photovoltaics. As an example, it is found that in some published papers the photocurrent is over-estimated, resulting in inaccurate efficiency value. Thus, a standard photovoltaic performance characterization procedure is necessary to advance the development of indoor photovoltaics.