Japanese Scientists Fabricate A Near-invisible Solar Cell Of 79% Transparency

A near-invisible solar cell has been fabricated by Japanese scientists after making indium tin oxide (ITO) and tungsten disulfide (WS2) as the base. ITO and WS2 act as a transparent electrode and a photoactive layer, respectively.

A report recently published mentions that PV device is also referred to as Schottky junction solar cell. This proves to be  an interface between a metal and a semiconductor, which further to supplythe band necessary for charge separation. The solar cell can boast of a power conversion efficiency that is 1,000 times as high as that of a reference device using a normal ITO electrode.

The scientists noted further that the cell could achieve transparency of 79% adding, “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,”.

New cell technology found its mention in the paper “Fabrication of near-invisible solar cell with monolayer WS2“, published across. The scientists also expressed confidence that the findings can contribute to the study of TMD-based near-invisible solar cells from fundamentals to truly industrialized stages.

The scientists have been quoted by the report as explaining, ““Once the generated carriers travel to the opposite electrode, power generation can be realized,”. The discrepancy in the work function (WF) between one of the electrodes and the semiconductor separates the photogenerated electron–hole pairs.

A member of the family of materials known as transition metal dichalcogenides (TMDs), WS2 is ideal for near-invisible solar cells, due to their suitable band gaps in the visible light range and highest absorption co-efficiency per thickness. Fabrication of the ITO–WS2 junction was made possible by sputtering ITO on quartz substrate and the WS2 monolayer was separately grown via chemical vapor deposition (CVD).

The idea of a near invisible solar cell is attractive for the many new applications it can create for solar PV, particularly on buildings, where solar can go beyond the rooftop to the sides too. Especially the south side which is not in any shade.