1. Fabrication of near-invisible solar cell with monolayer WS2.
- Author
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He, Xing, Iwamoto, Yuta, Kaneko, Toshiro, and Kato, Toshiaki
- Subjects
SOLAR cell design ,SCHOTTKY barrier ,TUNGSTEN electrodes ,SOLAR cells ,CHEMICAL vapor deposition ,MONOMOLECULAR films ,PHOTOVOLTAIC power systems - Abstract
Herein, we developed a near-invisible solar cell through a precise control of the contact barrier between an indium tin oxide (ITO) electrode and a monolayer tungsten disulfide (WS
2 ), grown by chemical vapor deposition (CVD). The contact barrier between WS2 and ITO was controlled by coating various thin metals on top of ITO (Mx /ITO) and inserting a thin layer of WO3 between Mx /ITO and the monolayer WS2 , which resulted in a drastic increase in the Schottky barrier height (up to 220 meV); this could increase the efficiency of the charge carrier separation in our Schottky-type solar cell. The power conversion efficiency (PCE) of the solar cell with the optimized electrode (WO3 /Mx /ITO) was more than 1000 times that of a device using a normal ITO electrode. Large-scale fabrication of the solar cell was also investigated, which revealed that a simple size expansion with large WS2 crystals and parallel long electrodes could not improve the total power (PT ) obtained from the complete device even with an increase in the device area; this can be explained by the percolation theory. This problem was addressed by reducing the aspect ratio (width/channel length) of the unit device structure to a value lower than a critical threshold. By repeating the experiments on this optimized unit device with an appropriate number of series and parallel connections, PT could be increased up to 420 pW from a 1-cm2 solar cell with a very high value (79%) of average visible transmission (AVT). [ABSTRACT FROM AUTHOR]- Published
- 2022
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