Flexible and Efficient Ultraviolet Photodetectors Based on One Dimensional MWCNT Filled Thermoplastic Polyurethane Nanocomposite Freestanding Films

Flexible ultraviolet (UV) photodetectors have attracted attention for many applications. Thermoplastic polyurethane (TPU) matrix nanocomposites have been prepared via the solution mixing method with varying wt% (0.1, 0.3, 0.5, and 1.0 wt%) of MWCNTs. Surface morphology of MWCNTs/TPU nanocomposite films with 0.1 wt% to 1.0 wt% has been studied using scanning electron microscopy (SEM), which shows the uniform dispersion of MWCNTs in TPU matrix, and coating of TPU on the surface of MWCNTs. UV photodetection performance and the mechanism of these MWCNTs/TPU nanocomposite films have also been studied. It was found that the responsivity of 1.710 A/W, and the EQE of 579.84% is found to be the maximum for the device made from the PUCNT1.0 sample. The detectivity of all the devices made from MWCNTs/TPU nanocomposite films has also been measured, which suggests that the detectivity of 8.09 × 10¹¹ Jones was observed to be maximum for the device made from the PUCNT1.0 sample. As the concentration of the MWCNT increases in the TPU matrix, the detectivity increases. These results provide us with clear guidelines to prepare the MWCNTs filled TPU nanocomposites for making free-standing, flexible, and efficient UV photo-detecting devices.