Effect of Zn/Sn Ratio on Perovskite Solar Cell Performance Applying Off-Stoichiometric Cu₂ZnSnS₄/Carbon Hole-Collecting Electrodes

Abstract

Low-cost inorganic hole-transporting materials (HTMs) accompanied by a printable carbon electrode is an efficient approach to address the limitation of material cost of perovskite solar cells (PSCs) and get this technology closer to commercialization. The present work is focused on optimizing the Zn/Sn ratio of Cu 2 ZnSnS 4 /carbon hole collectors in n−i− p structured PSCs, where CuInS 2 /carbon is applied as the reference hole collector. This composition regulation is a solution to address the challenge of composition-related defects of the Cu 2 ZnSnS 4 (CZTS) material. The Zn/ Sn ratio was tuned by the initial proportion of the zinc precursor during the nanoparticle (NP) synthesis using a heating-up procedure. It was found that the enhancement of the Zn/Sn ratio leads to a gradual increase of the optical band gap. More importantly, an increased density of B-type defect clusters [2Zn Cu + Zn Sn ] is confirmed using Raman results. Additionally, results from the cyclic voltammetry measurement show that by increasing the Zn/Sn value, the highest occupied molecular orbital (HOMO) of HTM is pulled down. These data match the upward trend of photovoltage. CZTS HTM with an optimal Zn/Sn ratio of 1.5 has a compatible energy level, along with the features of uniform and smooth coverage. The best efficiency of about 14.86% was obtained for optimal CZTS/carbon-based PSCs, which reaches from 14.86 to 15.49% after 25 days of aging.

HVHC-ESD-Induced Oxygen Vacancies: An Insight into the Phenomena of Interfacial Interactions of Nanostructure Oxygen Vacancy Sites with Oxygen Ion-Containing Organic Compounds

“…Furthermore, the intensity of the (002) peak in ZnO-W is slightly above (100), unlike ZnO-A, which is lower than the (100) peak (Figure a). Studies suggest that the broader peak with a shift concludes a possible reduction in crystallite size − along with residual stress in the lattice, indicating the oxygen vacancy of the structure. In this case, the HVHC-ESD ZnO-A samples show a better crystal structure formed with a low density of oxygen vacancy, while the ones synthesized in water (ZnO-W), due to the shortage of oxygen ions at the time of the plasma explosion, suffer from oxygen vacancy.…”

“…The photocatalytic activity of the ZnO-A and ZnO-W nanostructures was examined by the degradation of an organic dye, RhB, under an IRASOL SIM solar simulator (Figure S1). 35 The solar simulator provides an exact sunlight spectrum for the photodegradation experiment where 20 mg of each photocatalyst nanostructure was suspended in 50 mL of a 5 ppm RhB aqueous solution. The photocatalyst and RhB solution mixture was sonicated for better dispersion of the nanostructures.…”

Controlling Surface Morphology of Ag-doped ZnO as a Buffer Layer by Dispersion Engineering in Planar Perovskite Solar Cells

“…At the interface between the electrolyte and ETL, the capacity was calculated using Equation (1) [40]:…”

Simulation and Verification of the Direct Current Electric Field on Fabricating High Porosity f-MWCNTs Thin Films by Electrophoretic Deposition Technique

“…Among them, perovskite PVs emerge as a potential candidates due to their outstanding solar-to-power conversion efficiency . Many different groups of materials have been studied and applied to the hole transport layer (HTL), − electron transport layer (ETL), − and perovskite layer − to enhance the efficiency and stability of perovskite PVs. Carbon nanotubes (CNTs) have attracted worldwide attention to solve this problem due to their unique structure, outstanding mechanical strength and thermal conductivity, and versatile electronic properties. − In addition, they possess the limitless potential for decorated additional functions through chemical modification. − Many studies show that the presence of CNTs in perovskite PVs can passivate the defect sites in halide perovskites, preventing charge recombination in the perovskite layer. − Incorporating CNTs into PVs as a notable strategy in improving the device’s solar energy harvester capabilities, efficiency, stability, and low cost helps bring perovskite PVs and nanocarbon-based PVs closer to widespread commercialization. − …”