PeroCUBE evaluated the potential of metal halide perovskite semiconductors for photovoltaics (PV), light-emitting diodes (LEDs), and light-fidelity (LiFi)/visible light communication (VLC). To this end, atomic-scale simulations and perovskite ink engineering experiments were conducted to identify the most promising perovskite materials, including 2D/3D heterostructures. The performance of these materials was validated by processing small-area PV and LED devices using laboratory-scale deposition methods. Small-area solar cells achieved an efficiency greater than 23%, while small red, green and blue LEDs achieved external quantum efficiencies greater than 20%, 20% and 10%, respectively. The most promising layers for PV and LED devices were then scaled up to larger dimensions, initially to 1 cm² and subsequently to greater than 50 cm². For this purpose, we used sheet-to-sheet (S2S) processes for rigid substrates and roll-to-roll (R2R) methods for flexible substrates. Devices were then encapsulated using optimized packaging stacks to ensure long-term stability, particularly under damp heat conditions. Small and large-area PV and LEDs (red, green, blue) devices, whether rigid or flexible, were characterized to understand structure-property relationships. To this end, PeroCUBE developed a nanoscale characterization method featuring a novel type of dual-cavity laser made specifically for PeroCUBE, combining an interband cascade laser and a quantum cascade laser. PePV devices were evaluated as photodetectors for VLC applications before being implemented in wearable devices with indoor positioning capabilities, using lamps transmitting a unique identifier. Additionally, devices featuring small perovskite photodetectors for VLC and a larger perovskite PV module on the same substrate were demonstrated for energy-autonomous VLC systems with indoor positioning capabilities. Perovskite LEDs were also included in a multifunctional demonstrator capable of emitting light, harvesting energy from light, and sensing for LiFi, touch screens, and photoplethysmography. While perovskite LED devices showed high performance in small areas, large-area devices (50 cm²) exhibited insufficient operational lifetimes due to extrinsic defects causing rapid device shunting. To address this issue, the consortium adopted an alternative approach: the light emitted by blue organic LEDs (OLEDs) was down-converted to red or green using perovskite phosphors. This method significantly improved operational stability and enabled the demonstration of a LiFi optical link with a perovskite LED sending coded information to a perovskite photodetector. Life cycle and human health risk assessments were performed, with results indicating a similar impact of PeroCUBE technologies compared to existing ones, and even a relative advantage for flexible perovskite PV. Overall, the project met its objectives of advancing metal halide perovskite semiconductors for photovoltaics, LEDs, and VLC by demonstrating: (i) perovskite compositions leading to high PV and LED performance, (ii) encapsulation methods for both rigid and flexible devices, with rigid encapsulation passing five times the IEC 61215 damp heat requirements, and (iii) perovskite prototypes for indoor positioning using visible light communication protocols. A number of trade secrets could be generated during the project and one patent has been filed. Concerning dissemination, more than 40 manuscripts were published in scientific journals and more than 60 presentations were given at conferences, workshops and fairs.
