White-light photodetection enhancement and thin film impediment in Bi2S3 nanorods/thin-films homojunction photodetectors

The arrays of one-dimensional (1D) nanorods and thin films of Bi2S3 are synthesized using the hot-plate thermal vapor deposition technique. The controlled synthesis forms the homojunction of thin films of varying thicknesses and 1D nanorods and possesses stoichiometric orthorhombic crystal structures. The same chemical and crystalline composition with different morphological features offer to study the effects of homojunction and dimensions on the performances of the homojunction white-light Bi2S3 photodetectors. The responsivity and detectivity of the vertically standing arrays of 1D nanorods and ultrathin thin films of Bi2S3@15 photodetectors are obtained to be ∼749.3 mA/W and ~5.61 × 108 Jones, respectively. The response times of the Bi2S3 photodetectors to be very short of 162 ms. The study of varying thicknesses of the thin films shows that the larger thickness of thin films impedes the performances of Bi2S3 photodetectors. Also, the larger photo-active area provided by the arrays of nanorods enhances the photodetection in nanorods/thin films homojunction Bi2S3 photodetectors.