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Full-Text Articles in Nanoscience and Nanotechnology
Light-Activated Photocurrent Degradation And Self-Healing In Perovskite Solar Cells, Wanyi Nie, Jean-Christophe Blancon, Amanda J. Neukirch, Kannatassen Appavoo, Hsinhan Tsai, Manish Chhowalla, Muhammad A. Alam, Matthew Y. Sfeir, Claudine Katan, Jacky Even, Sergei Tretiak, Jared J. Crochet, Gautam Gupta, Aditya D. Mohite
Light-Activated Photocurrent Degradation And Self-Healing In Perovskite Solar Cells, Wanyi Nie, Jean-Christophe Blancon, Amanda J. Neukirch, Kannatassen Appavoo, Hsinhan Tsai, Manish Chhowalla, Muhammad A. Alam, Matthew Y. Sfeir, Claudine Katan, Jacky Even, Sergei Tretiak, Jared J. Crochet, Gautam Gupta, Aditya D. Mohite
Publications and Research
Solution-processed organometallic perovskite solar cells have emerged as one of the most promising thin-film photovoltaic technology. However, a key challenge is their lack of stability over prolonged solar irradiation. Few studies have investigated the effect of light soaking on hybrid perovskites and have attributed the degradation in the optoelectronic properties to photochemical or field-assisted ion migration. Here we show that the slow photocurrent degradation in thin-film photovoltaic devices is due to the formation of light-activated meta-stable deep-level trap states. However, the devices can self-heal completely by resting them in the dark for <1 min or the degradation can be completely prevented by operating the devices at 0°C. We investigate several physical mechanisms to explain the microscopic origin for the formation of these trap states, among which the creation of small polaronic states involving localized cooperative lattice strain and molecular orientations emerges as a credible microscopic mechanism requiring further detailed studies.
Electrokinetic Phenomena In Pencil Lead-Based Microfluidics, Yashar Bashirzadeh, Venkat Maruthamuthu, Shizhi Qian
Electrokinetic Phenomena In Pencil Lead-Based Microfluidics, Yashar Bashirzadeh, Venkat Maruthamuthu, Shizhi Qian
Mechanical & Aerospace Engineering Faculty Publications
Fabrication of microchannels and associated electrodes to generate electrokinetic phenomena often involves costly materials and considerable effort. In this study, we used graphite pencil-leads as low cost, disposable 3D electrodes to investigate various electrokinetic phenomena in straight cylindrical microchannels, which were themselves fabricated by using a graphite rod as the microchannel mold. Individual pencil-leads were employed as the micro-electrodes arranged along the side walls of the microchannel. Efficient electrokinetic phenomena provided by the 3D electrodes, including alternating current electroosmosis (ACEO), induced-charge electroosmosis (ICEO), and dielectrophoresis (DEP), were demonstrated by the introduced pencil-lead based microfluidic devices. The electrokinetic phenomena were characterized …