Inkjet-Printing of Methylammonium Lead Trihalide Perovskite-Based Flexible Optoelectronic Devices

In recent years, metal-organic methylammonium lead trihalide perovskite formulations have been extensively studied and employed as active materials in a range of photovoltaic and photodetector devices. Perovskite-based materials have gain popularity due to their unique optoelectronic properties which allow for simple device architecture to reach high energy harvesting efficiencies and responsivities over the whole visible light spectrum. These materials offer an advantage over conventional semiconductor materials and fabrication techniques as they do not require high temperatures or vacuum environments which are beneficial for fabricating devices on flexible, heat sensitive substrates. As the demand for low-cost and large-area flexible electronics increases, in part due to the rise of the internet of things (IoT), new routes in additive device fabrication techniques and advances in printable materials are required. In this work, digital inkjet-printing in ambient atmosphere is proposed as a fabrication pathway for perovskite based flexible photodetectors in thin-film device architectures. The devices consisting of a printed methylammonium lead trihalide perovskite layer and a printed Spiro-OMeTAD hole transport layer fabricated on indium tin oxide (ITO) coated Polyethylene terephthalate (PET) flexible substrates are shown to have an average responsivity at 0 V bias of 7.7 mu A/W in the range of 400 nm to 850 nm which is increased to 0.53 mA/W and 1.17 mA/W when biases of 0.5 V and 1.0 V are applied, respectively.