An eco-friendly universal strategy via ribavirin to achieve highly efficient and stable perovskite solar cells

TL;DR

This paper introduces a green molecular doping strategy using ribavirin to enhance the efficiency and stability of perovskite solar cells by reducing defects and improving energy levels, leading to higher PCE and long-term stability.

Contribution

The study demonstrates a novel, eco-friendly doping method with ribavirin that significantly improves perovskite solar cell performance and stability, validated through experimental and theoretical analyses.

Findings

PCE increased from 17.05% to 19.86% with ribavirin doping.

Long-term stability test shows 84.33% PCE retention after 900 hours.

Universal doping method applicable to different device structures.

Abstract

The grain boundaries of perovskite films prepared by the solution method are highly disordered, with a large number of defects existing at the grain boundaries. These defect sites promote the decomposition of perovskite. Here, we use ribavirin obtained through bacillus subtilis fermentation to regulate the crystal growth of perovskite, inducing changes in the work function and energy level structure of perovskite, which significantly reduces the defect density. Based on density functional theory calculations, the defect formation energies of VI, VMA, VPb, and PbI in perovskite are improved. This increases the open-circuit voltage of perovskite solar cells (PSCs) (ITO/PEDOT:PSS/perovskite/PCBM/BCP/Ag) from 1.077 to 1.151 V, and the PCE increases significantly from 17.05% to 19.86%. Unencapsulated PSCs were stored in the environment (humidity approximately 35+-5%) for long-term stability testing. After approximately 900 hours of storage, the PCE of the ribavirin-based device retains 84.33% of its initial PCE, while the control-based device retains only 13.44% of its initial PCE. The PCE of PSCs (ITO/SnO2/perovskite/Spiro-OMETAD/Ag) is increased from 20.16% to 22.14%, demonstrating the universality of this doping method. This universal doping strategy provides a new approach for improving the efficiency and stability of PSCs using green molecular doping strategies.