Solvothermal Growth of PbBi₂Se₄ Nano‐Flowers: A Material for Humidity Sensor and Photodetector Applications

Abstract

In the present work, lead bismuth selenide (PbBi 2 Se 4 ) nano-flowers are synthesized by using a simple solvothermal method. Humidity sensor and photodetector based on PbBi 2 Se 4 nano-flowers are fabricated on indium tin oxide (ITO) substrates and their sensing properties are investigated. Formation of PbBi 2 Se 4 is confirmed by XRD, EDS, and XPS whereas formation of nano-flowers is confirmed by SEM and TEM analysis. XRD analysis reveals the hexagonal crystal structure of PbBi 2 Se 4 phase with a ¼ b ¼ 4.22 Å, and c ¼ 17.42 Å. The surface morphology of PbBi 2 Se 4 clearly shows the formation of well-organized flower-like nanostructures which closely resembles the shape of Dahlia. The elemental mapping of chemical constituents obtained from SEM-EDS analysis shows uniform distribution of chemical constituents for the Pb, Bi, and Se in PbBi 2 Se 4 nano-flowers. The PbBi 2 Se 4 nano-flowersbased humidity sensor has a typical response time of %65 s and recovery time of %75 s. In case of PbBi 2 Se 4 nano-flowers-based photodetector, the response and recovery time are observed %121 and %123 s, respectively, under visible light illumination with photoresponsivity (5 Â 10 À6 ), photosensitivity (2.16%), and quantum efficiency (1.5 Â 10 4 ). The obtained results demonstrate the potential applications of solvothermally grown PbBi 2 Se 4 nano-flowers-based devices for humidity sensors and photodetectors. The ease of the present work is to develop novel material to obtain device quality humidity sensors and photodetectors.

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