New discovery regarding the arrangement of materials was found that able to change non-polarity materials to polarity materials and photovoltaic behaviour from certain non-photovoltaic, atomically flat (2D) materials. The resulted effects are able to enhance the photovoltaic properties in solar cell.
The two most non-polarity materials investigated are tungsten selenide (WSe2) and black phosphorus (BP), which have different crystal structures. Both are originally non-polar materials and unable to generate a photocurrent under the light. However, by stacking the sheets between WSe2 and BP together, polarization can be exhibited !!! When the light illuminates onto them, they are able to generate a current.
The key finding of this study lies in, “How do the WSe2 and BP align with each other ???” BP crystalline structure is like a mirror, reflective and symmetry in one plane. Meanwhile, WSe2 has three lines of mirror symmetry. Therefore, when the symmetry line of both materials aligns together, the polarity of both materials will increase. The stacking layer is the new way of method fabrication that can exhibit new properties and functions of the materials. The benefit from this research, hopefully that, we can enhance the efficiency of solar panels using nanomaterials that can generate more power using the solar panels.
Dr. Hidayani Binti Jaafar