Semiconductor Materials Solar Photovoltaic Cells †Free Samples

Question: Discuss about the Semiconductor Materials for Solar Photovoltaic Cells. Answer: Introduction: Most of the contemporary solar photovoltaic cells are made using silicon, which has an efficiency of about 25.6%. The theoretical limit of the efficiency obtainable when only one light absorbing material is used in the manufacture of the solar cells is 34%. The theoretical limit tends to increase and becomes about 46% when more than one light absorbing material is used. The use of tandem solar cells from two light-absorbing materials can then be such a good strategy in increasing the efficiency of photovoltaic solar cells(Kennedy, 2012). This will ensure increased efficiency at the same time maintaining low cost during manufacturing. The tandem solar cells in this analysis make use of silicon and metal-halide perovskite in the manufacture of the solar cells. Metal-halide perovskite is a material that has the ability to be manufactured at lower costs(Towler, 2014). This idea and analysis provides a platform for silicon-perovskite tandem solar cells and provides an avenue for the manufacture of low cost and high-efficiency solar cells. It is important to observe the reaction of various solar cells materials to incoming light in order to gain a better understanding of why tandem solar cells have the ability to enhance efficiency. Sunlight has a range of energies from ultraviolet light through visible light and infrared light. Ultraviolet light and visible light have higher levels of energy that infrared light. A solar cell makes use of semiconducting material to absorb the light from the sun and change it into electrical power. The semiconductor has a special feature called bandgap that enables it to absorb light as well as extra energy from the absorbed light in the form of electricity. A tradeoff exists when the bandgap of absorbing material is being chosen. A smaller bandgap results into a wider energy range being absorbed from the sun thereby more current is being generated(Paranthaman, 2015). However, a smaller bandgap translates to a lower voltage of extracting the electrical current and since power is a produ ct of voltage and the current, it means there will be low power production. A contemporary silicon solar cell produces 0.5 V 12-volt solar panel produces 12*0.5= 17 V at peak Using a current of 3.5 A for the panel, the wattage can be estimated Power=Voltage * Current=17*3.5 =59.6 W A metal-halide perovskite, on the other hand, produced a voltage of 1.5V per cell Assuming a 12 voltage panel as the case with the silicon solar cell Total voltage=1.5*12=50V at peak Current=3.5 A Power of the solar panel=3.5*51 =178.5 W Efficiency of the metal-halide perovskite= (178.5-50)/50*100 =257% efficient This means that metal-halide perovskite conserves energy more than twice as much as the contemporary silicon solar cells. Metal-halide perovskite produces very high voltages as a result of the elimination of tradeoff as discussed below Tandems are important in reducing this tradeoff. When two absorbers are used, each of the absorbers will specialize in one portion of the solar spectrum as opposed to the case of a single absorber that will have to cover the whole spectrum(Towler, 2014). While the first absorber will be specializing in the ultraviolet and visible photons, the second absorber that will be lying just beneath the first one will specialize on the infrared photons. The use of these specialized absorbers greatly minimizes losses of energy when sunlight is lost in the form of heat rather than electric current. In this analysis, the metal-halide perovskite is used as the first absorber in trapping ultraviolet and visible light while silicon serves as the second absorber, capturing infrared light. The design develops two layers that are unique to a tandem solar cell and are not used in the contemporary solar cells. An electrically connecting layer known as a tunnel junction was made using silicon and was used to connect the two light absorbing materials. A transparent electrode was also made. The electrode conducts electricity at the same time allowing light to pass through it. The purpose of the transparent electrode was to connect the solar cell to the external wires to allow extraction of power(Hardyman, 2013). The transparent electrode was made from a mesh of silver nanowires, which resembles a chain link fence made of wires, which are thousands of times thinner than the diameter of the human hair. Using such layers, it is possible to start designing the other layers in solar cells with multiple layers. Metal-halide perovskite is increasingly becoming one of the most popular materials for photovoltaic cells. The term perovskite is used to define a crystalline structure of a material that is composed of three components in a ratio of 1:1:3. The metal-halide perovskite that is used in the making photovoltaic is three parts halide, one part metal, and one part an organic molecule. A semiconductor is formed when iodine, lead and methyl ammonium, which are the three parts of metal-halide perovskite used in photovoltaic, is combined. References Hardyman, R. (2013). How a Solar-Powered Home Works. New York: The Rosen Publishing Group. Kennedy, D. (2012). Rooftop Revolution: How Solar Power Can Save Our Economy-and Our Planet-from Dirty Energy. London: Berrett-Koehler Publishers. Paranthaman, M. P. (2015). Semiconductor Materials for Solar Photovoltaic Cells. Oxford: Springer. Towler, B. F. (2014). The Future of Energy. London: Elsevier Science.