Otsuka Munechika, Kurokawa Yuki, Ding Yi, Juangsa Firman Bagja, Shibata Shogo, Kato Takehito, Nozaki Tomohiro
School of Engineering, Tokyo Institute of Technology 2-12-1 O-okayama, Meguro-ku Tokyo 152-8550 Japan
Department of Mechanical Engineering, National Institute of Technology, Oyama College 771 Nakakuki, Oyama Tochigi 323-0806 Japan.
RSC Adv. 2020 Mar 27;10(21):12611-12618. doi: 10.1039/d0ra00804d. eCollection 2020 Mar 24.
Silicon nanocrystals (SiNCs) featuring size-dependent novel optical and electrical properties have been widely employed for various functional devices. We have demonstrated SiNC-based hybrid photovoltaics (SiNC-HPVs) and proposed several approaches for performance promotion. Recently, owing to the superiorities such as low power operation, high portability, and designability, organic photovoltaics (OPVs) have been extensively studied for their potential indoor applications as power sources. SiNCs exhibit strong light absorption below 450 nm, which is capable of sufficient photocurrent generation under UV irradiation. Therefore, SiNC-HPVs are expected to be preferably used for energy harvesting systems in indoor applications because an indoor light source consists of a shorter wavelength component below 500 nm than solar light. We successfully demonstrated SiNC-HPVs with a PCE as high as 9.7%, corresponding to the output power density of 34.0 μW cm under standard indoor light irradiation (1000 lx). In addition, we have found that SiNC defects working as electron traps influence the electrical properties of SiNCs substantially, a thermal annealing process was conducted towards the suppression of defects and the improvement of the SiNC-HPVs performance.
具有尺寸依赖性新颖光学和电学性质的硅纳米晶体（SiNCs）已被广泛应用于各种功能器件。我们已经展示了基于SiNC的混合光伏器件（SiNC-HPVs），并提出了几种提高性能的方法。最近，由于低功耗运行、高便携性和可设计性等优势，有机光伏器件（OPVs）因其作为室内电源的潜在应用而受到广泛研究。SiNCs在450nm以下表现出强烈的光吸收，这使得在紫外线照射下能够产生足够的光电流。因此，由于室内光源比太阳光包含更多低于500nm的短波长成分，SiNC-HPVs有望优先用于室内应用的能量收集系统。我们成功展示了具有高达9.7%的光电转换效率（PCE）的SiNC-HPVs，这对应于在标准室内光照射（1000 lx）下34.0 μW cm的输出功率密度。此外，我们发现作为电子陷阱的SiNC缺陷会极大地影响SiNCs的电学性质，因此进行了热退火处理以抑制缺陷并提高SiNC-HPVs的性能。
