CdS/ZnO Nanostructure Thin-Film-Based Flexible Photosensor With Tuneable Photoresponse

Nanostructured text metal–oxide composite-based flexible photodetectors are gaining attention due to their applications in various fields. However, achieving the required photocurrent and response time is usually a challenge in the development of photodetectors. In this article, an ZnO-CdS composite-based flexible thin film photosensor is fabricated to achieve desirable photocurrent and response time. The proposed flexible photosensor overcomes the low photocurrent of only text CdS-based photosensors and the slow response of only ZnO-based photosensors. The photosensor is fabricated using a printed interdigitated electrode over a flexible polyethylene terephthalate (PET) substrate. In this case, nanostructured CdS, ZnO, and text CdS–ZnO composite thin films are used as photoactive materials. Different proportions of ZnO and CdS are used to study the effect of the light on composites. The sensor with active material 1:2-CdS/ZnO composite demonstrates a 40 times higher photocurrent with respect to the CdS-based sensor. Furthermore, the improved response time of 9.79 s is achieved for the 1:2-CdS/ZnO composite. The response time is observed to be ~23% less with respect to ZnO based sensor. The proposed sensor demonstrates the capability of having the desired photocurrent and response time by tuning the material proportion in the composite.