Interface Engineering of the High-Efficiency Perovskite Solar Cells with Triphenylene Discotic Liquid Crystals

Herein, we incorporated Hexa-alkoxy triphenylene (HAT6)-based Discotic Liquid Crystals(DLCs) for the interfacial engineering of the Perovskite Solar cell (PSC). Experimental studies demonstrate that a discotic liquid crystal interface formation between the perovskite and a hygroscopic hole transporter Spiro-OMeTAD can make the device more stable and efficient. Surface anchoring of the perovskite with the DLCs slower the degradation mechanism of the devices and inhibits the lead iodide formation. Different concentration of HAT6 was used for interfacial layer formation. Devices with liquid Crystal interfaces with a lower thickness (40nm) provide higher power conversion efficiency, up to 19%. The reference devices gave an efficiency value up to 17%. HAT6-incorporated device layers proved better hydrophobicity and PL quenching than reference devices. The incident photon-to-electron ratio was significantly improved due to less recombination at the Perovskite-Spiro-OMeTAD interface. Overall, the results illustrate the DLC materials among the potential candidates for providing stable and efficient perovskite photovoltaics.