Synthesis and characterization on all-inorganic solar cell: Combined theoretical and experimental approach

Inorganic perovskites with the general formula of ABX₃ are categorized as one of the promising candidates to be used as an absorber layer in solar cells. In this structure, A is a cation, B is usually lead (Pb), and X is a halide (Cl, Br, I). These materials have exciting specifications in terms of physical and electronic properties and a wide range of applications such as LED, lasers, transistors, etc. In recent years, new types of inorganic perovskites are incorporated into the solar cells, establishing a new era in perovskite photovoltaics. Adjustable bandgap using different compositions have made them one of the promising materials in order to be utilized along with conventional perovskite materials. One of the advantages of using inorganic perovskites instead of traditional organic perovskites (such as MAPbI₃) is higher thermal and UV resistance, which is really important in terms of using these materials in commercial perovskite solar cells. However, inorganic perovskites are much more sensitive to the moisture and oxygen, which limit their application in places with high relative humidity. In this project, we focus on synthesizing different types of inorganic perovskites with other physical and optoelectronic properties to make a solar cell device that can work under high relative humidity like here in Thailand. We believe that using unique surface treatments and doping; the inorganic perovskites could be stabilized for long term use. We will use alkali cations such as Cs to synthesize different types of perovskites and study the effect of other halides on the respective solar cells' stability and efficiency. Next, we will examine the impact of doping and surface treatment on thin films' physical properties. The variables such as thickness, temperature, and time of reaction will be optimized and further used to make future devices. Besides, we are developing a simulation program to compare the result from experiments with the computed data. This is of great importance because this will reduce the number of experiments in terms of trials and errors and give us predictable solar cell device features.