Study of Photo-Conductivity in MoS2 Thin Films Grown in Low-Temperature Aqueous Solution Bath

An experimental study over the optical response of thin MoS2 films grown by chemical bath deposition (CBD) method is presented. As two important factors, the effect of bath temperature and growth time are considered on the photocurrent generation in the grown samples. The results show that increasing the growth time leads to better optical response and higher difference between dark and photocurrent. For higher bath temperatures the layer loses its uniformity and the current reduces. Better performance of optical response is obtained for t=90min and T=70oC. We also studied the effect of post-annealing on the performance and quality of thin films. The I-V measurements show no current flow for annealed films because of rupture of the film structure. Temporal response of the films to light source ON and OFF states is also studied and the results showed relaxation of photocurrent after about several seconds. The importance of the MoS2 thin films obtained by CBD method is low-temperature process and large area of fabricated layers which can be used in many applications.