Temperature- and light-dependent photoconductivity studies of thermally evaporated WTe 2 thin film for photodetection application

In this work, photo- and temperature-dependent electrical properties of thermally deposited WTe 2 thin film have been reported. The n-type behaviour of WTe 2 film of thickness ~ 122 nm has been observed. The dark conductivity analysis revealed that thermally activated conduction mechanism is responsible for charge carrier transport. In the presence of light, WTe 2 shows higher current than dark conditions response towards light with two activation energies of ~ 0.374 eV and 0.692 eV signifying the dominance of bimolecular recombination under light illumination. On–off cycle determined the respective current variation with different light intensities. The fabricated device possesses responsivity ~ 0.36 mA/W and detectivity of ~ 3.2 × 10 9 Jones.