Unfolding photophysical properties of poly(3-hexylthiophene)-MoS2 organic-inorganic hybrid materials: an application to self-powered photodetectors

Self-powered photodetectors have grown as inevitable members of the optoelectronic device family. However, it is still challenging to achieve self-powered photodetection with good responsivity in the visible spectrum region. Herein, we report solution-processable poly(3-hexylthiophene) (P3HT)-molybdenum disulfide (MoS2) organic-inorganic hybrid material, which can be used as the active layer in self-powered photodetectors. The morphological and structural properties of the synthesized P3HT-MoS2 hybrid material has been discussed using atomic force microscopy and transmission electron microscopy, respectively. The hybrid material loaded with 1 wt% MoS2 has shown an enhancement in the self-assembly of polymer in the form of fibrillar formation and excellent structural features in terms of pi-conjugation. The self-powered photodetectors have been fabricated in indium tin oxide (ITO) coated glass/P3HT-MoS2/Al configuration. The merit of P3HT-MoS2 hybrid photodetectors is measured under the illumination of 470, 530, and 627 nm light in ambient conditions. P3HT-MoS2 photodetectors show significantly higher responsivity and detectivity. The photo responsivity and detectivity in P3HT-MoS2 devices are found to be 271.2 mA W-1 and 4.4 x 10(10) jones at zero bias, respectively, for 470 nm light with the optical power density of 74.1 mu W cm(-2). Furthermore, the photocurrent switching behaviour at periodic illuminations of 1 Hz has also been examined for P3HT-MoS2 self-powered photodetectors.