US research and development of new photovoltaic materials can absorb ultraviolet and infrared light

According to reports recently organized by the Physicists Organization Network, the United States scientists have developed a new type of photovoltaic materials, solar panels manufactured using them, low cost and high efficiency. For more than 40 years, scientists have been hoping to develop bulk photovoltaic materials. In addition to using ultraviolet energy, they can also use visible and infrared energy. New materials have finally made their way.

The new material was developed by scientists from the University of Pennsylvania and Drexel University and has three outstanding advantages. First, it produces thinner solar panels than silicon-based solar panels that currently dominate the market. Second, its raw materials are cheaper than the materials used in current high-end thin-film solar cells. Third, this material is a ferroelectric material, which means that its polarity can be turned on and off, contributing to the theoretical limitation of solar cell materials beyond the current photoelectric conversion efficiency.

Part of the reason for the low efficiency of solar panels is that particles collected from the sun will scatter around when they enter the solar cell. If you want all the particles to flow in one direction, you need multiple layers of different guiding materials. The particles will lose a little bit for each layer of material, which reduces the energy efficiency of solar cells. New materials make fewer solar cell guide layers and therefore less energy loss; moreover, ferroelectric materials use less energy to direct particles.

It took the scientists five years to finally design the new material, consisting of perovskite crystals of potassium citrate and lanthanum gallate. The results show that its performance is far better than the current ferroelectric materials and can absorb 6 times more solar energy. The researchers said that further improvement and adjustment of the composition of the material will further increase energy efficiency.

Jonathan Spanneil of Drexel University’s Materials Science and Engineering said: “The new material is surprising because it consists of cheap, non-toxic and abundant elements, unlike the current high-efficiency thin-film solar cells. Composite semiconductor materials."

Researchers use a set of tools to prove that new materials can move energy in one direction rather than stagger between layers, thus minimizing energy loss. This ability is called the body-photovoltaic effect and has been known to scientists since the 1970s. But until now, scientists have observed this effect only in the ultraviolet rays. Actually, most of the sunlight's energy is in visible light and Infrared spectrum. With new materials, they finally observed this effect in visible light and infrared light.

Moreover, they also proved that by adjusting the percentage of new material components, the energy band gap of the material can be reduced. Spanneil said: "The band gap of this material is in the UV range, but only 10% increase in Niobium Niobate will allow its bandgap to enter the visible range and approach the ideal value of solar energy conversion efficiency. "(Liu Xia)