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

Abstract

This work investigates the optical, structural, and photo-physical properties of PCPDTBT/cesium lead bromide (CsPbBr3) perovskite quantum dots (QDs) composite for optoelectronic devices. The composite was prepared by processing the PCPDTBT and CsPbBr3 QDs via the solution blending method. Incorporating CsPbBr3 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/CsPbBr3 QDs composite (4 wt%) to study their electronic and charge transfer features. Significant variation in source-to-drain current (IDS) 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/CsPbBr3 QDs-based FET show enhanced current with illumination, which could be attributed to the photo-generated charge carriers.