Preparation and properties of passivation film layers spray coated flexible Cu(In, Ga)Se2 solar cells

Recently, the flexible thin film solar cells such as the organic solar cells and Cu(In, Ga)Se₂ (CIGS) solar cells have been attracting much attention as the photovoltaic devices, because it has many advantages such as simple process with a light weight, and its flexible large area applications. In addition, solar cells as an energy source can be applicable to the unmanned aerial vehicle (UAV) and IoT system, which is the interconnection of identifiable objects through the wireless internet systems. In order to improve the reliability of the devices, it is desirable to optimize the passivation materials and structures. The passivation treatment is a key technology in order to prevent the devices from atmospheric oxygen and moisture. As one of the methods to commercialize the flexible solar cells, hybrid type encapsulation films using organic and inorganic materials can be effective in blocking the penetration of water and oxygen into the devices.