Fully printed flexible perovskite solar modules with improved energy alignment by tin oxide surface modification

TL;DR

This paper presents a fully printed flexible perovskite solar module with improved efficiency and stability achieved through surface modification of tin oxide layers, demonstrating potential for commercial applications.

Contribution

Introduction of a fullerene-substituted alkylphosphonic acid dipole layer to enhance interface quality in fully printed flexible perovskite solar cells.

Findings

Achieved 17.0% PCE with negligible hysteresis.

Retained 95% PCE after 3000 bending cycles.

Maintained 90% PCE after 500 hours damp-heat testing.

Abstract

Fully printed flexible perovskite solar cells (f-PSCs) show great potential for the commercialization of perovskite photovoltaics owing to their compatibility with high-throughput roll-to-roll (R2R) production. However, the challenge remains in the deficiency in controlling interfacial recombination losses of the functional layer, causing remarkable loss of power conversion efficiency (PCE) in industrial production. Here, a fullerene-substituted alkylphosphonic acid dipole layer is introduced between the R2R-printed tin oxide electron transport layer and the perovskite active layer to reduce the energetic barrier and to suppress surface recombination at the buried interface. The resulting f-PSCs exhibit a PCE of 17.0% with negligible hysteresis, retain 95% of their initial PCE over 3000 bending cycles and achieve a T95 lifetime of 1200 h under 1 sun and 65 degreeC in nitrogen atmosphere. Moreover, the fully printed flexible perovskite solar mini-modules (f-PSMs) with a 20.25 cm2 aperture area achieve a PCE of 11.6%. The encapsulated f-PSMs retain 90% of their initial PCE after 500 h damp-heat testing at 65 degreeC and 85% relative humidity (ISOS-D3). This work marks an important progress toward the realization of efficient and stable flexible perovskite photovoltaics for commercialization.