Long Thermal Stability of Inverted Perovskite Photovoltaics Incorporating Fullerene-based Diffusion Blocking Layer

TL;DR

This study demonstrates that incorporating a thick fullerene buffer layer in inverted perovskite solar cells significantly enhances their thermal stability, achieving over 1000 hours of heat lifetime at 60°C by preventing diffusion-related degradation.

Contribution

The paper introduces a novel use of a thick fullerene buffer layer to block diffusion and improve the thermal stability of inverted perovskite photovoltaics.

Findings

Diffusion of metal electrode into perovskite causes degradation at high temperatures.

Thick fullerene buffer layer effectively isolates perovskite from metal electrode.

Achieved over 1000 hours of stable operation at 60°C.

Abstract

In this article, the stability of p-i-n perovskite solar cells is studied under accelerated heat lifetime conditions (60 oC ,85oC and N2 atmosphere). By using a combination of buffer layer engineering, impedance spectroscopy and other characterization techniques, we propose the interaction of the perovskite active layer with the top Al metal electrode through diffusion mechanisms as the major thermal degradation pathway for planar inverted perovskite photovoltaics (PVs) under 85oC heat conditions. We show that by using thick solution processed fullerene buffer layer the perovskite active layer can be isolated from the top metal electrode and improve the lifetime performance of the inverted perovskite photovoltaics at 85 oC. Finally, we present an optimized solution processed inverted perovskite PV device using thick fullerene-based diffusion blocking layer with over 1000 hours accelerated heat lifetime performance at 60oC.