A Review on Eco-Friendly Quantum Dot Solar Cells: Materials and Manufacturing Processes

Power conversion efficiencies of colloidal quantum dot solar cells, which have focused mainly on lead chalcogenide systems until recently, have increased rapidly and currently exceed 12%. Among the many issues involved in commercialization of this technology as a consumer product, lead-based materials in these systems must be replaced. This requires the use of a low-cost, low-loss, and non-toxic chemical, along with the development of an eco-friendly manufacturing process. Herein, we review recent progress in ecofriendly colloidal quantum dot photovoltaics, with a focus on two aspects. First, we examine non-toxic or less-toxic quantum dot materials designed for efficient thin-film based solar cells by considering factors such as bandgap tunability, exciton binding energy, and more. We then present the performance of quantum dot solar cells using these green quantum dot materials, and discuss the scientific and technological issues facing them. Second, we review fabrication methods of quantum dot thin films with low-cost, lowwaste, and non-toxic chemicals, for use in eco-friendly manufacturing processes.