Desenvolvimento de células solares baseadas em pontos quânticos de CsPbI3 e TiO2 dopado com cobre (II)

Abstract

The increasing demand for clean energy sources has driven the development of emerging photovoltaic technologies, among them quantum dot-based solar cells. This work aimed to develop solar cells using quantum dots of CsPbI₃ and an electron transport layer of TiO₂ doped with copper (II) ions, synthesized by the sol-gel method. Samples were prepared with 0%, 1%, 2% and 3% Cu²⁺ doping, with subsequent characterization by structural (XRD), morphological (MEV, MET), optical (DRS) and electrochemical (VC, DPV, EIS) techniques. The results revealed that the anatase phase of TiO₂ was preserved in all samples, with small structural distortions associated with ion substitution by Cu²⁺. The morphological analyses indicated good dispersion of copper up to 2%, while the sample with 3% showed signs of agglomeration. Electrochemical analyses showed that doping with 2% copper resulted in less separation of redox peaks and higher electrochemical activity, indicating an improvement in charge transport and less electronic recombination. The I-V curves of the solar cells revealed that the sample with 2% doping also showed the best photovoltaic parameters, with an increase in short-circuit current (Jsc) and open-circuit voltage (Voc), compared to TiO₂ without dopant. Copper (II) doping has therefore been shown to be an efficient strategy for the optimization of TiO₂ properties in CsPbI₃-based photovoltaic devices. Although the efficiency values are still modest, the work confirms the technical feasibility of the proposal and points out paths for future advances, such as environmental control during manufacturing, use of passivating layers and exploration of other metal dopants.