Fully Scalable and Stable CsPbI2Br Solar Cells Realized by an All-Spray-Coating Process.

Spray-coating is a scalable and time-efficient technique for the development of large-area metal halide perovskite (MHP) solar cells. However, a bottleneck still exists toward the development of fully scalable n-i-p-type MHP solar cells particularly on spray-coating the hole transporting layer (HTL). Here, we present a reliable strategy of spray-coating the HTL by using MoO2 nanoparticles with small amounts of poly(triarylamine) (PTAA) binders to ensure uniform coverage and efficient charge extraction. By spray-coating all layers except the Au electrode, we achieve high and scalable efficiencies of 14.26 and 13.88% for CsPbI2Br unit cells (0.12 cm2) and submodules (25 cm2), respectively. We then extend toward an all-spray-coating process by spray-coating carbon black as the top counter electrode, resulting in a submodule efficiency of 10.08%. Finally, we also demonstrate good long-term stability of the submodules under damp heat conditions (85 °C/85% relative humidity) over 1000 h.

Self-powered flexible all-perovskite X-ray detectors with high sensitivity and fast response.

Perovskite materials have demonstrated superior performance in many aspects of optoelectronic applications including X-ray scintillation, photovoltaic, photodetection, and so on. In this work, we demonstrate a self-powered flexible all-perovskite X-ray detector with high sensitivity and fast response, which can be realized by integrating CsPbBr3 perovskite nanocrystals (PNCs) as the X-ray scintillator with a CH3NH3PbI3 perovskite photodetector. The PNCs scintillator exhibits ultra-fast light decay of 2.81 ns, while the perovskite photodetector gives a fast response time of ∼0.3 µs and high-specific detectivity of ∼2.4×1012 Jones. The synergistic effect of these two components ultimately leads to a self-powered flexible all-perovskite X-ray detector that delivers high sensitivity of 600-1,270 µC/mGyaircm3 under X-ray irradiation and fast radiation-to-current response time.

Enhanced Weak-Light Detection of Perovskite Photodetectors through Perovskite/Hole-Transport Material Interface Treatment.

Enhancement in weak-light detection and other photodetection properties was observed for organic-inorganic halide perovskite photodetectors as a result of benzylammonium iodide (BzAI) treatment at the methylammonium lead triiodide (MAPbI3) and hole-transport layer (HTL) interface. After treatment, growth of the two-dimensional Ruddlesden-Popper perovskite phase was observed at the MAPbI3 surface, which shifted the overall surface work function upwards and thus effectively facilitated charge transfer across the MAPbI3/HTL interface. As a result, the fully fabricated device with 10 mg/mL (BzAI/isopropanol) treatment exhibited shorter rise time (trise) and decay time (tdecay) of 53 and 38 µs, respectively, compared to trise and tdecay of 214 and 120 µs, respectively, for the pristine MAPbI3 sample. In addition, the BzAI-treated device exhibited larger linearity compared to the pristine MAPbI3 sample, demonstrating a high and stable specific detectivity of 1.49 × 1013 to 2.14 × 1013 Jones under incident light intensity of 10-3 to 100 mW/cm2, respectively.