Suppressed decomposition of organometal halide perovskites by impermeable electron-extraction layers in inverted solar cells

The area of thin-film photovoltaics has been overwhelmed by organometal halide perovskites. Unfortunately, serious stability concerns arise with perovskite solar cells. For example, methyl-ammonium lead iodide is known to decompose in the presence of water and, more severely, even under inert conditions at elevated temperatures. Here, we demonstrate inverted perovskite solar cells, in which the decomposition of the perovskite is significantly mitigated even at elevated temperatures. Specifically, we introduce a bilayered electron-extraction interlayer consisting of aluminium-doped zinc oxide and tin oxide. We evidence tin oxide grown by atomic layer deposition does form an outstandingly dense gas permeation barrier that effectively hinders the ingress of moisture towards the perovskite and-more importantly-it prevents the egress of decomposition products of the perovskite. Thereby, the overall decomposition of the perovskite is significantly suppressed, leading to an outstanding device stability

Utilizing the unique charge extraction properties of antimony tin oxide nanoparticles for efficient and stable organic photovoltaics

Simultaneously enhancing device performance and longevity, as well as balancing the requirements on cost, scalability, and simplification of processing, is the goal of interface engineering of organic solar cells OSCs . In our work, we strategically introduce antimony Sb3 cations into an efficient and generic n type SnO2 nanoparticles NPs host during the scalable flame spray pyrolysis synthesis. Accordingly, a significant switch of conduction property from an n type character to a p type character is observed, with a corresponding shift in the work function WF from 4.01 0.02 eV for pristine SnO2 NPs to 5.28 0.02 eV for SnO2 NPs with 20 mol. Sb content ATO . Both pristine SnO2 and ATO NPs with fine tuned optoelectronic properties exhibit remarkable charge carrier extraction properties, excellent UV resistance and photo stability being compatible with various state of the art OSCs systems. The reliable and scalable pristine SnO2 and ATO NPs processed by doctor blading in air demand no complex post treatment. Our work offers a simple but unique approach to accelerate the development of advanced interfacial materials, which could circumvent the major existing interfacial problems in solution processed OSC