Thermal analysis of metal organic precursors for functional Cu doped NiOx hole transporting layer in inverted perovskite solar cells the role of solution combustion chemistry in Cu doped NiOx thin films processing

TL;DR

This study explores the synthesis of Cu-doped NiOx thin films via solution combustion, analyzing their thermal properties and effectiveness as hole transport layers in inverted perovskite solar cells, highlighting optimal annealing conditions for device performance.

Contribution

It introduces a detailed thermal and structural analysis of Cu:NiOx thin films synthesized by solution combustion, demonstrating their application as efficient hole transport layers in perovskite solar cells.

Findings

Cu:NiOx thin films crystallize at 300°C regardless of fuel ratio.

Films annealed at 300°C yield high-efficiency perovskite solar cells.

Thermal analysis distinguishes between thin film and bulk combustion processes.

Abstract

Low temperature solution combustion synthesis emerges as a facile method for synthesis of functional metal oxides thin films for electronic applications. We study the solution combustion synthesis process of Cu:NiOx using different molar ratios (w/o, 0.1 and 1.5) of fuel acetylacetone (Acac) to oxidizer (Cu, Ni Nitrates) as a function of thermal annealing tempera-tures 150, 200 and 300 oC. The solution combustion synthesis process, in both thin films and bulk Cu:NiOx, is investigated. Thermal analysis studies using TGA and DTA reveal that the Cu:NiOx thin films show a more gradual mass loss while the bulk Cu:NiOx exhibits a distinct combustion process. The thin films can crystallize to Cu:NiOx at annealing temperature of 300 oC irrespective to the Acac/Oxidizer ratio whereas lower annealing temperatures (150 and 200 oC) produce amorphous materials. A detail characterization study of solution combustion synthesized Cu:NiOx including XPS, UV-Vis, AFM and Contact angle measurements is presented. Finally, 50 nm Cu:NiOx thin films are introduced as HTLs within the inverted perovskite solar cell device architecture. The Cu:NiOx HTL annealed at 150 and 200 oC provided PVSCs with limited functionality whereas efficient triple-cation Cs0.04(MA0.17FA0.83)0.96 Pb(I0.83Br0.17)3 based PVSCs achieved for Cu:NiOx HTLs annealed at temperature 300 oC.