The development of methodologies for synthesizing carrier-transporting materials is critical for optoelectronic device fabrication. Amorphous
metal oxides have emerged as potential carrier transport materials for
perovskite tandem solar cells and flexible electronics due to their ease of fabrication and excellent electronic properties. However,
perovskite solar cells employing amorphous
metal oxides as the electron-transporting layers (ETLs) remain inefficient. This research describes a moderate
dehydration reaction for the low-temperature synthesis of amorphous SnOx. We investigated this amorphous SnOx as the ETL for
perovskite solar cells and demonstrated a maximum power conversion efficiency (PCE) of 20.4%, the greatest efficiency ever attained with an amorphous
metal oxide ETL produced below 100 °C. Remarkably, the device maintained 85% of its initial efficiency for more than 4800 h. Furthermore, flexible
perovskite solar cells based on this amorphous SnOx have a maximum PCE of 11.7%. Finally, this amorphous SnOx was used to fabricate LEDs and exhibited a maximum external quantum efficiency of over 3%.