We report the fabrication and characterization of visible and near-infrared-resistive photodetector using horizontally aligned titanium tri sulfide (TiS₃) nanoribbons. The fabrication process employed micro-electromechanical system, photolithography and dielectrophoretic (DEP) methods. The interdigitated electrodes (IDE) fingers were fabricated using photolithography and thin-film metallization techniques onto the Si/SiO₂ substrate, and then TiS₃ nanoribbons were horizontally aligned in between IDE using DEP. The fabricated device was first characterized in absence of light and then, the photodetector-based characteristics were obtained by illuminating it with fiber-coupled laser beam. These characteristics were optimized by varying wavelength and power density of the laser beam. The present photodetector shows a maximum responsivity of 5.22 × 10² A/W, quantum efficiency of 6.08 × 10², and detectivity of 1.69 × 10⁹ Jones. The switching times, i.e., response and recovery times were found to be 1.53 and 0.74 s, respectively, with 1064 nm wavelength and 3.4 mW/mm² power density of the laser beam. Also, the effect of O₂ adsorption on nanoribbons has been studied and it is found that adsorbed O₂ acts as electron acceptor and decreases the conductivity of the photodetector. Experimentally, it is found that the photoresponse of the horizontally aligned TiS₃ nanoribbons is better than that of a randomly oriented TiS₃ nanoribbon-based photodetector. Finally, the performance of the present photodetector was compared to that of the previous ones that were found to outperform the reported ones. The additional advantages of the photodetector include excellent stability and portability from which it may be concluded that TiS₃ nanoribbons can be a promising candidate for application in nanoscale electronic and optoelectronic devices.

Exfoliation of bulk WS₂ powder has been conducted by ultrasonication, and its layer by layer peeling is monitored by HRTEM, XRD, UV-Vis, and Raman spectroscopy. HRTEM confirms the peeling process and selected area electron diffraction pattern shows the crystallinity of nanosheets which is in accordance with the X-ray diffraction results. Raman and UV-visible spectroscopies further confirm the exfoliation of WS₂ to nanosheets having a few layers. A photodetector developed from a few-layered WS₂ film is used for photodetection over wide wavelength and temperature ranges. The detector exhibits the highest sensitivity at 635 nm with a value of 382% at 77 K against a value of 138% at 300 K, while the response and the recovery time are ∼78 ms and ∼40 ms, respectively. Temperature, excitation wavelength, and laser power-dependent studies show the threshold limit of its faithful operation. Temperature-dependent photoresponsivity and sensitivity are explained in terms of the carrier–phonon scattering dependent transport mechanism. The scattering cross-section analysis using the density functional theory model reveals that it is the in-plane and out-of-plane acoustic modes that play a key role in carrier transport, rather than the optical phonons. The influence of atmospheric constituents (N₂, O₂) on detector performance is checked by a successive exposure to dry N₂ and ambient air flow. A 14% reduction in photoresponsivity under O₂ exposure is observed and suitable analysis is given in terms of O₂ induced enhancement of the electron–hole recombination process, leading to a loss of photogenerated carriers. The sensor's cycling performance remains unaffected even after a prolonged exposure in ambient conditions (55% RH), showing its chemical stability even for long-term use.