Monolithic Organic/Colloidal Quantum Dot Hybrid Tandem Solar Cells via Buffer Engineering.

Area of Science:

• Materials Science
• Renewable Energy
• Nanotechnology

Background:

• Monolithic hybrid tandem solar cells (TSCs) integrating colloidal quantum dots (CQDs) and organic molecules offer broad light absorption.
• Current organic/CQD hybrid TSCs lag behind single-junction CQD solar cells in performance.
• A key challenge is preventing CQD solvent damage to underlying organic layers.

Purpose of the Study:

• To enhance the performance of organic/CQD hybrid TSCs beyond single-junction devices.
• To address the solvent penetration issue in solution-processed hybrid solar cells.
• To improve current matching and overall power conversion efficiency (PCE).

Main Methods:

• Development of a strategic optical structure incorporating a multibuffer layer.
• Introduction of a dual near-infrared (NIR) organic absorber to complement CQD absorption.
• Fabrication and characterization of monolithic hybrid TSC devices.

Main Results:

• A multibuffer layer effectively prevented CQD solvent penetration.
• A dual NIR organic absorber significantly improved current matching to 15.2 mA cm^-2.
• The hybrid TSCs achieved a record power conversion efficiency (PCE) of 13.7%.

Conclusions:

• The devised optical structure overcomes previous performance limitations in hybrid TSCs.
• The new design demonstrates superior performance compared to individual single-junction cells.
• This work represents a significant advancement in CQD-based hybrid tandem solar cell technology.