Study of charge transport in cesium lead bromide perovskite quantum dots and PCPDTBT composites: an application to photosensitive FETs

This work investigates the optical, structural, and photo-physical properties of PCPDTBT/cesium lead bromide (CsPbBr 3 ) perovskite quantum dots (QDs) composite for optoelectronic devices. The composite was prepared by processing the PCPDTBT and CsPbBr 3 QDs via the solution blending method. Incorporating CsPbBr 3 QDs with different weight % (wt%) ratio in PCPDTBT influences its optoelectronic properties. UV–vis absorption spectroscopy, photoluminescence (PL), and atomic force microscopy measurements were used to analyze their optical and morphological properties. We observed that incorporating 4 wt% QDs in PCPDTBT enhanced its light absorption and charge transfer properties. Increased carrier lifetime for PCPDTBT/QDs (4 wt%) was observed from PL decay measurements. Further, we fabricated the field effect transistors (FETs) of pristine PCPDTBT and PCPDTBT/CsPbBr 3 QDs composite (4 wt%) to study their electronic and charge transfer features. Significant variation in source-to-drain current (I DS ) and carrier mobility has been observed. A substantial increased output current was observed for composite FET than pristine PCPDTBT-based FET due to charge transfer from QDs to PCPDTBT. Both PCPDTBT and PCPDTBT/CsPbBr 3 QDs-based FET show enhanced current with illumination, which could be attributed to the photo-generated charge carriers.