Enhancing morphology and charge extraction of low-bandgap bulk-hetrojunction on zno nanorod by ultrasonic treated hydrothermal growth

Ultrasonic treatment is used to control the morphology of ZnO nanorod array grown by hydrothermal method, providing large-scale synthesis of uniform nanorod array and efficient exciton dissociation. The high quality of ZnO nanorod is critical for the performance of organic/inorganic hybrid solar cells based on a blend of the low-bandgap polymer:fullerene. As a result, the power conversion efficiency (PCE) was improved from 2.97 to 5.54 %, with a short-circuit current density (J_sc) of 15.11 mA/cm², an open-circuit voltage (V_oc) of 0.71 V, and a fill factor (FF) of 51.61% under 100mW/cm² irradiation.