Silicotungstate, a Potential Electron Transporting Layer for Low-Temperature Perovskite Solar Cells

Area of Science:

• Materials Science
• Renewable Energy
• Photovoltaics

Background:

• Perovskite solar cells (PSCs) require efficient electron transporting layers (ETLs) for optimal performance.
• Traditional ETLs like TiO2 often require high processing temperatures, limiting their use in flexible PSCs.

Purpose of the Study:

• To investigate the application of lithium silicotungstate (Li-ST) as a low-temperature processed ETL for planar PSCs.
• To evaluate the performance of Li-ST ETLs compared to conventional TiO2 ETLs.

Main Methods:

• Fabrication of Li-ST thin films via a low-temperature solution process.
• Characterization of Li-ST film morphology and thickness.
• Fabrication and performance testing of CH3NH3PbI3 PSCs with Li-ST ETLs.
• Spectroscopic analysis (time-resolved photoluminescence, transient photocurrent measurements) to understand charge transport dynamics.

Main Results:

• Dense and uniform Li-ST films were successfully prepared at low temperatures.
• A 60 nm-thick Li-ST ETL resulted in a PSC with a power conversion efficiency (PCE) of 14.26%, outperforming TiO2 ETLs (PCE = 12.27%).
• Li-ST demonstrated more efficient electron collection and longer electron lifetime compared to TiO2.

Conclusions:

• Li-ST is a promising ETL material for PSCs, enabling high efficiency with low-temperature processing.
• The superior performance of Li-ST suggests its potential for fabricating flexible PSC devices.