Fully Inkjet-Printed Green-Emitting PEDOT:PSS/NiO/Colloidal CsPbBr3/SnO2 Perovskite Light-Emitting Diode on Rigid and Flexible Substrates

After establishing themselves as promising active materials in the field of solar cells, halide perovskites are currently being explored for fabrication of low-cost, easily processable, and highly efficient light-emitting diodes (LEDs). Despite this, the highest efficiencies reported for perovskite-based LEDs (PeLEDs) are achieved through spin coating or vacuum evaporation deposition techniques, which are not adequate, in most of the cases, for an industrial-scale production. Additionally, the long-term stability is still a big handicap, even though all inorganic perovskites, such as CsPbBr3, are found to be more stable to external variables. In this context, herein, the fabrication of fully inkjet-printed (IJP) CsPbBr3-based PeLEDs in ambient conditions, on rigid and flexible substrates, on a proof-of-concept basis, with the successful incorporation of NiO and SnO2 as hole- and electron-selective contacts, respectively, is reported. Despite the moderate luminance (324 cd m−2) value obtained, this result paves the way toward the development of upscalable fabrication of PeLEDs based on deposition techniques with controlled spatial resolution.The authors wish to thank the financial support from the European Commission via FET Open Grant (862656, DROP-IT), MINECO (Spain) for grant PID2019-105658RB-I00 (PRITES project), Ministry of Science and Innovation of Spain under Project STABLE (PID2019-107314RB-I00), and Generalitat Valenciana via Prometeo Grant Q-Devices (Prometeo/2018/098)

High Photovoltage of 1 V on a Steady-State Certified Hole Transport Layer-Free Perovskite Solar Cell by a Molten-Salt Approach

The determination of certified efficiency values for perovskite solar cells from current–voltage sweeps is under growing discussion. Here, we report for the first time a certified steady-state solar efficiency for a hole transport layer (HTL)-free perovskite cell of 12.6% measured continuously at maximum power point in an accredited laboratory. By applying a molten-salt-based MAPbI₃ precursor solution, dense filling and improved perovskite crystallization inside the nanoporous graphite-based monolithic contact scaffold of the cell are achieved. A stabilized photovoltage as high as 1 V is achieved, representing the highest <i>V</i>_OC reported for HTL-free MAPbI₃-based devices. Charge transport properties are determined by switching from open- to short-circuit conditions. Strong and stable quenching of the photoluminescence indicates effective transportation and extraction of the photoexcited primary charge carriers. The existence of an efficient HTL-free device suggests that these cells are more of an n-p junction type than of n-i-p junction nature

High Photovoltage of 1 V on a Steady-State Certified Hole Transport Layer-Free Perovskite Solar Cell by a Molten-Salt Approach

The determination of certified efficiency values for perovskite solar cells from current–voltage sweeps is under growing discussion. Here, we report for the first time a certified steady-state solar efficiency for a hole transport layer (HTL)-free perovskite cell of 12.6% measured continuously at maximum power point in an accredited laboratory. By applying a molten-salt-based MAPbI₃ precursor solution, dense filling and improved perovskite crystallization inside the nanoporous graphite-based monolithic contact scaffold of the cell are achieved. A stabilized photovoltage as high as 1 V is achieved, representing the highest <i>V</i>_OC reported for HTL-free MAPbI₃-based devices. Charge transport properties are determined by switching from open- to short-circuit conditions. Strong and stable quenching of the photoluminescence indicates effective transportation and extraction of the photoexcited primary charge carriers. The existence of an efficient HTL-free device suggests that these cells are more of an n-p junction type than of n-i-p junction nature

High Photovoltage of 1 V on a Steady-State Certified Hole Transport Layer-Free Perovskite Solar Cell by a Molten-Salt Approach

The determination of certified efficiency values for perovskite solar cells from current–voltage sweeps is under growing discussion. Here, we report for the first time a certified steady-state solar efficiency for a hole transport layer (HTL)-free perovskite cell of 12.6% measured continuously at maximum power point in an accredited laboratory. By applying a molten-salt-based MAPbI₃ precursor solution, dense filling and improved perovskite crystallization inside the nanoporous graphite-based monolithic contact scaffold of the cell are achieved. A stabilized photovoltage as high as 1 V is achieved, representing the highest <i>V</i>_OC reported for HTL-free MAPbI₃-based devices. Charge transport properties are determined by switching from open- to short-circuit conditions. Strong and stable quenching of the photoluminescence indicates effective transportation and extraction of the photoexcited primary charge carriers. The existence of an efficient HTL-free device suggests that these cells are more of an n-p junction type than of n-i-p junction nature

Characterization of perovskite solar cells: Towards a reliable measurement protocol

Lead halide perovskite solar cells have shown a tremendous rise in power conversion efficiency with reported record efficiencies of over 20% making this material very promising as a low cost alternative to conventional inorganic solar cells. However, due to a differently severe “hysteretic” behaviour during current density-voltage measurements, which strongly depends on scan rate, device and measurement history, preparation method, device architecture, etc., commonly used solar cell measurements do not give reliable or even reproducible results. For the aspect of commercialization and the possibility to compare results of different devices among different laboratories, it is necessary to establish a measurement protocol which gives reproducible results. Therefore, we compare device characteristics derived from standard current density-voltage measurements with stabilized values obtained from an adaptive tracking of the maximum power point and the open circuit voltage as well as characteristics extracted from time resolved current density-voltage measurements. Our results provide insight into the challenges of a correct determination of device performance and propose a measurement protocol for a reliable characterisation which is easy to implement and has been tested on varying perovskite solar cells fabricated in different laboratories