High-Performance Core/Shell of ZnO/TiO2 Nanowire with AgCl-Doped CdSe Quantum Dots Arrays as Electron Transport Layer for Perovskite Solar Cells.

Jin Mo Kim,Sung Won Hwang,Bong Soo Lee

doi:10.3390/molecules25173969

Abstract

Most previous studies of perovskite core/shell structures have been based on ZnO/TiO2 nanowires (NWs), which are not suitable for high photoelectric conversion efficiency. Here, core/shell ZnO/TiO2 NWs with AgCl-doped CdSe quantum dots were fabricated as an electron transport layer (ETL) for perovskite solar cells, based on ZnO/TiO2 arrays. We designed CdSe with AgCl dopants that were synthesized by a colloidal process. An improvement of the recombination barrier (Rct1), due to shell supplementation with AgCl-doped CdSe quantum dots, improved the open circuit voltage, the fill factor, and the adsorption capacity of CH3NH3PbI3 perovskite with NWs. The enhanced cell steady state was attributable to TiO2 with AgCl-doped CdSe QD supplementation. A maximum power conversion efficiency of 15.12% was attained in an atmospheric environment. The mechanism of the recombination and electron transport in the perovskite solar cells becoming the basis of ZnO/TiO2 core/shell arrays was investigated to represent the merit of ZnO/TiO2 core/shell arrays as an electron transport layer in effective devices. These results showed an uncomplicated approach for restraining non-radiative recombination loss in hetero-structure core/shell arrays to significantly improve perovskite solar cell performance and increase the effectiveness of photovoltaics.

Highlights

Perovskite photovoltaics based on the combination of organo–lead halide photon energies have gained intensive interest owing to their excellent photoelectric efficiencies and potential for use in flexible devices
The mechanism of the recombination and electron transport in the perovskite solar cells becoming the basis of ZnO/TiO2 core/shell arrays was investigated to represent the merit of ZnO/TiO2 core/shell arrays as an electron transport layer in effective devices
It is clear that the heterogeneous perovskite modification by ZnO/TiO2 with AgCl-doped CdSe quantum dot (QD) entirely coated the structures between the NWs

Summary

Introduction

Perovskite photovoltaics based on the combination of organo–lead halide photon energies have gained intensive interest owing to their excellent photoelectric efficiencies and potential for use in flexible devices. To improve the device stability and performance of perovskite photovoltaics, studies have proposed several strategies such as a CdSe quantum dot (QD)/PCBM hybrid for improved carrier diffusion [9,10], changing the iodide ion concentration [11], introducing a SnO2 protective structure between perovskite layers and ZnO nanowires (NWs) with TiO2 modification for carrier recombination [12,13,14]. With its wide direct band gap (Eg = 3.37 eV at room temperature) [17,18], ZnO exhibits a different structure in photovoltaics [19,20,21] and is considered a promising alternative to the present TiO2 arrays with AgCl-doped CdSe QDs, characterized by rapid carrier recombination [22,23].

Methods

Results

Conclusion