Morphological Tuning of Bi2Se3 Thin Films for Photoelectrochemical Performance

In the present report, we have reported the bismuth selenide (Bi2Se3) thin films for solar cell application. The synthesis of bismuth selenide (Bi2Se3) thin film by using modified chemical bath deposition i. e. arrested precipitation technique (APT). The Physico‐chemical properties of synthesized Bi2Se3 thin films are studied as a function of surfactants. The XRD patterns confirm the nanocrystalline nature. The SEM images reveal morphological transitions from fibrous reticulate structure to spongy balls‐like structure. The compositional analysis confirms bismuth and selenium in good stiochiometry. Optical studies show presence of a absorption in the visible range with a band gap in the range of 1.5 eV to 1.9 eV. All these results reveal that surfactant‐assisted Bi2Se3 thin film is a better candidate for PEC performance. This is the graphical presentation of the growth mechanism of bismuth selenide thin films. The growthof thin films takes place byion by ion condensation. It follows the mechanism of Ostwald ripening law. When there is change in the surfactant the morphology of bismuth selenide thin film also changes. Here first image shows the fibrous reticulate structure without use of surfactant. When SDS is used as a surfactant lamellar spheres are observed. Finally when CTAB is used as a surfactant spongy balls like morphology is observed. This morphological tuning of bismuth selenide is highly beneficial for solar cell applications.