Studies utilizing microinjections of thyrotropin-releasing hormone (TRH) were performed to determine potentially sensitive limbic brain sites to the ulcerogenic effect of TRH. Administration of TRH into the central nucleus of the amygdala (CEA) produced a high (80%) incidence of gastric lesions and also significantly stimulated acid secretion. Microinjections of TRH into other brain sites including superior colliculus, medial septum, substantia nigra and the hippocampus (CA1 area) were ineffective. Intra-CEA TRH-induced gastric lesions and acid secretion were prevented by vagotomy. These results indicate that the amygdala is of importance for mediating the ulcerogenic effect of brain TRH through peripheral vagal pathways.

Self-assembled monolayers (SAMs) are becoming widely utilized as hole-selective layers in high-performance p-i-n architecture perovskite solar cells. Ultrasonic spray coating and airbrush coating are demonstrated here as effective methods to deposit MeO-2PACz; a carbazole-based SAM. Potential dewetting of hybrid perovskite precursor solutions from this layer is overcome using optimized solvent rinsing protocols. The use of air-knife gas-quenching is then explored to rapidly remove the volatile solvent from an MAPbI3 precursor film spray-coated onto an MeO-2PACz SAM, allowing fabrication of p-i-n devices with power conversion efficiencies in excess of 20%, with all other layers thermally evaporated. This combination of deposition techniques is consistent with a rapid, roll-to-roll manufacturing process for the fabrication of large-area solar cells.

Over the past six years, researchers have investigated the use of spray coating to fabricate perovskite solar cells (PSCs), with the aim of demonstrating its viability as an industrial manufacturing process. This spotlight on applications outlines the key benefits of this coating technology and summarizes progress made to date, with attention focused on varied efforts to control the crystallization and uniformity of the perovskite layer. The emerging understanding of processes required to create smooth, dense spray-cast perovskite films has recently led to the demonstration of fully spray-cast PSCs with a power conversion efficiency of 19.4%.

We use ultrasonic spray-coating to sequentially deposit thin films of tin oxide, a triple-cation perovskite and spiro-OMeTAD, allowing us fabricate perovskite solar cells (PSCs) with a champion reverse scan power conversion efficiency (PCE) of 19.4% on small-area substrates. We show that the use of spray-deposition permits us to rapidly (>80 mm s −1 ) coat 25 mm × 75 mm substrates that were divided into a series of devices each with an active area of 15.4 mm 2 , yielding an average PCE of 10.3% and a peak PCE of 16.3%. By connecting seven 15.4 mm 2 devices in parallel on a single substrate, we create a device having an effective active area of 1.08 cm 2 and a PCE of 12.7%. This work demonstrates the possibility for spray-coating to fabricate high efficiency and low-cost perovskite solar cells at speed.

The development of scalable deposition methods for perovskite solar cell materials is critical to enable the commercialization of this nascent technology. Herein, we investigate the use and processing of nanoparticle SnO2 films as electron transport layers in perovskite solar cells and develop deposition methods for ultrasonic spray coating and slot-die coating, leading to photovoltaic device efficiencies over 19%. The effects of postprocessing treatments (thermal annealing, UV ozone, and O2 plasma) are then probed using structural and spectroscopic techniques to characterize the nature of the np-SnO2/perovskite interface. We show that a brief “hot air flow” method can be used to replace extended thermal annealing, confirming that this approach is compatible with high-throughput processing. Our results highlight the importance of interface management to minimize nonradiative losses and provide a deeper understanding of the processing requirements for large-area deposition of nanoparticle metal oxides.

Perovskite solar cells utilising NiO and TiO2 charge-extraction layers, deposited via high-speed, low substrate-temperature reactive electron-beam evaporation, achieve 15.8% PCE.

Back-contact PSCs are fabricated by depositing charge-selective electrodes and MAPbI3 into micron-sized polymeric grooves, micro-modules are formed by serially-connecting grooves.

Simultaneous GI-WAXS diffraction patterns and JV measurement of IBC solar cells during in situ anneal.

We use ultrasonic spray-coating to fabricate cesium-containing triple-cation perovskite solar cells with a power-conversion efficiency of up to 17.8%. Our fabrication route involves a brief exposure of the partially wet spray-cast films to a low vacuum, a process that is used to control film crystallization. We show that films that are not vacuum-exposed are relatively rough and inhomogeneous, while vacuum-exposed films are smooth and consist of small and densely packed perovskite crystals. The process techniques developed here represent a step toward a scalable and industrially compatible manufacturing process capable of creating stable and high-performance perovskite solar cells.

Spray-coating is a deposition technique that is widely used in industry and could in principle be used to fabricate perovskite photovoltaic (PV) devices at low cost and high volume. As with any deposition technique, the fabrication of thin films requires optimization of a range of parameter space in order to control film uniformity and homogeneity. This is particularly important in PV fabrication as the quality of the thin film has an important effect on device efficiency. This Perspective summarizes the developments in spray-cast perovskite solar cells made over the past few years, with particular attention paid to strategies employed to control the crystallization of the perovskite. Steady progress has now been made with spray-cast perovskite PV devices recently demonstrated having a power conversion efficiency of 18.3%. We highlight trends within the research field and discuss challenges that will be necessary to drive such techniques toward practical application.

We utilise spray-coating under ambient conditions to sequentially deposit compact-TiO 2 , mesoporous-TiO 2 , CH 3 NH 3 PbI (3−x) Cl x perovskite and doped spiro-OMeTAD layers, creating a mesoporous standard architecture perovskite solar cell (PSC). The devices created had an average power conversion efficiency (PCE) of 9.2% and a peak PCE of 10.2%; values that compare favourably with control-devices fabricated by spin-casting that had an average efficiency of 11.4%. We show that our process can be used to create devices having an active-area of 1.5 cm 2 having an independently verified efficiency of 6.6%. This work demonstrates the versatility of spray-coating as well as its potential as a method of manufacturing low-cost, large-area, efficient perovskite devices.

PCDTBT conductivity is 105 times higher when doped with LITFSI & TBP, perovskite devices employing doped PCDTBT achieve 15.9% PCE.