Organic photosynthetic solar cells above silicon solar cells

As the great specter of climate change continues to grow in the future, the search for viable, renewable energy sources becomes increasingly important.

Solar energy has long been recognized as an essential ingredient in our future for clean energy. With a little inspiration from nature, solar energy may have become an even more promising perspective than previously thought.

Photosynthesis is the storage process of solar energy in which plants absorb sunlight, carbon dioxide and water and convert them into energy (in the form of sugar) and oxygen. The traditional image of photosynthesis is that long wavelength light (far red and infrared light, with wavelengths longer than 700 nanometers) contains low energy photons. We used to think that light at these long wavelengths was not “energetic” enough to produce oxygen. In other words, we thought that photosynthesis could only take place with the light that we humans can see.

But the discovery of a new type of chlorophyll – called Chl f – is changing the way we think about photosynthesis. This new green molecule has the greatest ability of any cholorophyll to absorb red-shifted light, that is, light with a wavelength longer than the human eye can perceive. This discovery of chlorophyll f challenges traditional views of the physical limits of photosynthesis.

Explicitly, the general chemical equation for plant photosynthesis is given by the following equation:

6CO2 + 6H2O + hV —-> C6H12O6 + 6CO2

In this double replacement reaction, complex compounds are synthesized from smaller ones. In this particular equation, hv represents the amount of energy of one photon, while the process known as electron transfer begins after photosynthesis is complete. One way to increase the electron transfer of chlorophyll is to replace the magnesium (Mg) atom with another metal such as copper (Cu) or iron (Fe). While the introduction of too much heavy metal can cause damage to sensitive plant tissues, the result will certainly be effective.

Organic Photosynthetic Solar Cells (PSC) are designed to convert light into electricity in four steps, similar to that of the natural process. First the maximum absorption of light; which in turn forms an excited state of electrons as a second step. Then the excitation diffusion in areas where charge separation occurs and eventually this leads to charge transfer.

The typical characteristic of a photovoltaic device is described as-

I = Io {exp[e/nkT(U-IRs)-1]+[(U-IRs)/Rsh]-Iph

This equation can be explained in the following terms: Io is the dark current, e is the charge of the electron, n is the diode ideality factor, U is the applied voltage, Rsh is considered the series resistance, Iph is the photoelectric flow. The PSC can be synthesized in layers in the following order: chlorophyll, a catalyst, argose and graphene.

The ONE square inch prototype consists of a photosensitive molecule, including the photosynthetic powerhouse chlorophyll, embedded in a water-based gel sandwiched between copper and plastic electrodes. Unlike traditional, many of which contain toxic elements such as cadmium, biologically derived materials can be safely released into the environment after use. The flexibility of the cell can be an ideal choice for covering irregular surfaces, large pieces can even be rolled up or folded for easy transport.

It was estimated that the efficiency of a single solar cell produced by this method achieved less than 1% of that of silicone cells. Although sensor data was not available, a current could be detected using an ohm meter. Although this number is small, it confirms the hypothesis that living chlorophyll can be extracted and used to convert light energy into electrical energy.

However, varying the cell’s configuration, improved layering techniques, extracting chlorophyll from multiple sources and different extraction methods can be used to improve the performance of a photosynthetic solar cell with chlorophyll. Hence, as in the past, solar panels and cells have replaced many electricity-supplying technologies in the past decade, now within a few years with the quest for better lifestyle changes, organic cells are sure to increase.

Source by Ria Ghosh