Ultrasensitive flexible broadband photodetectors achieving pA scale dark current

Organolead halide perovskite is a newly emerging low-cost, solution-processable material with a broadband absorption from the ultraviolet (UV) to visible (Vis) region, which has attracted a great deal of interest in high-performance optoelectronic devices. However, some practicable applications need a cover of UV–Vis–NIR region for photoelectric conversion, a task that remains a significant challenge for further extending the absorption toward the near-infrared radiation (NIR) region. Here, to the best of our knowledge, we prove for the first time an ultrasensitive flexible broadband photodetector based on porous organolead perovskite-phthalocyanine heterostructure, which combines the synergetic properties of high UV–Vis absorbance of perovskite with enhanced NIR absorption for triclinic lead phthalocyanine. The photosensitivity of the as-prepared devices reaches up to 10 4 at a low intensity of 10 mW cm −2 , which is among the largest values reported for broadband photodetectors. Significantly, performed at room temperature, the device achieves a pA scale dark current along with an ultrafast response speed of less than 0.6 ms for as-adopted full spectra. Our results provide an easy and promising route to develop low-cost, flexible and highly sensitive UV–Vis–NIR photodetectors. Semiconductor physics: Energy saving flexible broadband hybrid photodetector Energy efficient and flexible alternative photodetector that detects both visible and invisible light comes closer to real life than ever. A group of researchers from China has developed an organic-inorganic hybrid photodetector that outperforms conventional inorganic like Si and InGaAs-based photodetectors in at least two aspects: broader detection spectral range and much lower dark current. Thanks to the structural flexibility of two hybrid photosensitive materials, methyl-ammonium lead halide and lead phthalocyanine, the team engineered the large area sub-micron thick photodetector with porous structures, which is the key to reducing the standby power consumption by more than 30 times compared to the best InGaAs and Si-based photodetectors. More importantly, the hybrid photodetector needs no additional apparatus or power to cool it for continuous operation, in contrast to the InGaAs photodetector.