Methyl-ammonium lead iodide perovskite crystallizes in different structures depending on the temperature: orthorhombic, tetragonal and cubic. An important point to be considered is the effect of the microscopic properties of the different structures on the optical and photovoltaic properties. Using first principles we obtain the absorption coefficients that will determine the absorption of solar radiation. In order to analyze the contributions of the different atoms to the absorption coefficients we split them into a many-species expansion. Using a similar methodology we also split the efficiencies as a many-species expansion. It allows the contribution of the atomic species to be identified and quantified to the absorption coefficients and to the solar cell efficiency of the different phases. Additionally the effect of the cell thickness w is quantified.

甲基铵碘化铅钙钛矿根据温度以不同的结构结晶：正交晶，四方晶和立方晶。要考虑的重要一点是不同结构的微观特性对光学和光伏特性的影响。使用第一原理，我们获得吸收系数，该吸收系数将决定太阳辐射的吸收。为了分析不同原子对吸收系数的贡献，我们将它们分为多个种类的扩展。使用类似的方法，我们还将效率分为多种扩展。它可以识别和量化原子种类对不同相的吸收系数和太阳能电池效率的贡献。此外，单元厚度的影响w被量化。