Hybrid Phototransistors Based on Bulk Heterojunction Films of Poly(3-hexylthiophene) and Zinc Oxide Nanoparticle

摘要

Hybrid phototransistors (HPTRs) were fabricated on glass substrates using organic/inorganic hybrid bulk heterojunction films of p-type poly(3-hexylthiophene) (P3HT) and n-type zinc oxide nanoparticles (ZnO_(NP)). The content of ZnO_(NP) was varied up to SO wt % in order to understand the composition effect of ZnO_(NP) on the performance of HPTRs. The morphology and nanostructure of the P3HT:ZnO_(NP) films was examined by employing high resolution electron microscopes and synchrotron radiation grazing angle X-ray diffraction system. The incident light intensity (P_(IN)) was varied up to 43.6 μW/cm~2, whereas three major wavelengths (525 nm, 555 nm, 605 nm) corresponded to the optical absorption of P3HT were applied. Results showed that the present HPTRs showed typical p-type transistor performance even though the n-type ZnO_(NP) content increased up to 50 wt %. The highest transistor performance was obtained at 50 wt %, whereas the lowest performance was measured at 23 wt % because of the immature bulk heterojunction morphology. The drain current (I_D) was proportionally increased with P_(IN) due to the photocurrent generation in addition to the field-effect current. The highest apparent and corrected responsivities (R_A = 4.7 A/W and Re = 2.07 A/W) were achieved for the HPTR with the P3HT:ZnO_(NP) film (50 wt % ZnO_(NP)) at P_(IN) = 0.27 μW/cm~2 (555 nm).