CdSe QDs modified cellulose microfibrils for enhanced humidity sensing properties

A great demand exists for the customisation and downsizing of gas sensors. Materials of interest commonly utilise some sort of charge transport phenomena to allow a sensing response, f.e. increase or decrease of the electric signal. Here we implemented sensing principles into solar cells (SC) and presented a novel concept of two-in-one SC and humidity sensor. Potentially, this could also allow the adjustment of SC performance according to humidity conditions. To better display the application potential, we modified solely the SC photoactive layer, which was prepared by infusion of CdSe quantum dots (QDs) into cellulose microfibrils, following a newly compiled synthetic route. When semiconductive fillers are implemented in composite materials, the sensing response usually consists only of the swelling of composite material, but with successful implementation, we have promoted more complex mechanisms due to multiple contributions. All of the segments were stabilised sufficiently to prepare devices and characterised in detail. We showed it is possible to boost and tailor the sensing performance of photoactive semiconducting materials based on swelling sensors by implementing the quantum confinement phenomena. In conclusion, the novel QD-microfibrils within a thin-film SC proved viable for a dual-functioning photovoltaic swelling-type semiconductor-organic hybrid gas sensor.

Automated summary

There is a high demand for customized and downsized gas sensors. This study implemented sensing principles into solar cells, creating a two-in-one solar cell and humidity sensor. By modifying the photoactive layer of the solar cell, the sensing performance of the semiconducting material was significantly improved.