Rare earth (Sm/Eu/Tm) doped ZrO2 driven electro-catalysis, energy storage, and scaffolding in high-performance perovskite solar cells

Abstract

Current work presents the first report on the modification of zirconia (ZrO2) by doping it with the lanthanides oxides i.e. [samarium, europium, and thulium] forming a [Sm/Eu/Tm] co-doped ZrO2 system. Lanthanide doping tailored the structure of host material by causing considerable bandgap energy shrinkage from 4.04 to 3.57 eV and reduction in the crystallite size from 67.92 to 45.23 nm. Profound electro-catalytic potential was reflected analyzed via linear sweep voltammetry showing the excellent of developed catalytic towards H2 evolution with lower overpotential i.e. 133 mV and Tafel slope of 119.3 mV dec−1. While for O2 evolution, the electro-catalyst succeeded in gaining overpotential and Tafel slope values of 310 mV and 294.8 mV dec−1, respectively. With such values, this material has surpassed the conventional electro-catalysts and is proved to be an excellent hydrogen producing electro-catalyst. The electrical charge storage potential was analyzed for [Sm/Eu/Tm] co-doped ZrO2 decorated nickel foam electrode for development into a super-capacitor. This electrode was impressively stable for 10 cycles after 20 days checked through cyclic voltammetry. Furthermore, an augmented specific capacitance of 447 F g−1 was achieved by the doped electrode when compared with the pristine one approaching 83.69 F g−1. The electrical energy storage capacity of [Sm/Eu/Tm] co-doped ZrO2 is even higher than the conventionally used metal oxides. In terms of the interfacial electrode-electrolyte, electrochemical impedance spectroscopy was done expressing the excellent ionic diffusion and electrochemically active sites for [Sm/Eu/Tm] co-doped ZrO2 electrode with minimal resistance. The developed doped system was used a spacer layer in a cesium lead halide perovskite solar cells having planar architecture. The spacer layer containing solar cell device succeeded in gaining a power conversion efficiency of 16.31% and a fill factor of 78% evaluated via photo-current measurements carried out under artificial solar irradiance. The impressively higher fill factor shows the effective passivation and scaffolding by the [Sm/Eu/Tm] co-doped ZrO2. The associated device was also marked by negligible hysteresis. Chrono-potentiometry and chrono-amperometry expressed commendable accelerated service lives for 100 min inside an electrolyte. The lanthanide co-doped ZrO2 is an effective material for the utilization in energy systems associated with the electro-catalysis of water, charge storage electrode for super-capacitors, and photovoltaic solar to electrical energy conversion.