Utilization of Cu₂ZnSnS₄ (CZTS) as a Tribo-Positive Layer for Energy Harvesting, Tactile Sensing, and Audio Recording

Abstract

To enlist a new tribo-positive material for triboelectric nanogenerator (TENG) fabrication, successful application of copper zinc tin sulfide (CZTS) as a tribo-positive active material is demonstrated by fabricating two devices, one for energy generation and the other for a flexible self-powered sensor (FTENG) for tactile/motion/audio stimuli. Memory writing on CZTS via charge generation is also demonstrated using Kelvin probe microscopy (KPFM). The nanogenerator achieved a peak-to-peak output voltage of 700 V and an output current of 50 μA, delivering an instantaneous output power of 3.5 mW across a 32 MΩ load. The FTENG operates efficiently as a biomechanical energy harvester and a self-powered tactile/motion sensor. Sensitivity tests reveal a high sensitivity of 155–335 VN–1 for low-range forces, positioning the FTENG as a promising candidate for self-powered electronic skin in robotics and wearable sensor technology. In addition, the utility of the FTENG as an audio sensor is demonstrated by recording an actual audio file.