Photo-carrier extraction by triboelectricity for carrier transport layer-free photodetectors

Efficient carrier extraction is essential for high performance optoelectronic devices, such as solar cells and photodetectors. Conventional strategies to separate photogenerated carriers typically involve the fabrication of a p-n junction by doping and the use of carrier selective charge transport layers. However, these techniques often require high temperature processes or costly materials. In this work, we demonstrate an innovative and simple approach of extracting photogenerated carriers from organometallic halide perovskites utilizing triboelectricity. The triboelectric device can be easily fabricated at low temperature using inexpensive materials on plastic substrates, enabling it to be readily integrated into self-powered optoelectronic devices. As a proof-of-concept, we fabricated a triboelectrics-assisted perovskite photodetector, which enabled us to study the surface charges generated using different electrical contacts and bending conditions performed by the device. With the assistance of a triboelectric charge-induced electric field, the photocurrent and transient photoresponses were significantly enhanced. Furthermore, we integrated the plastic triboelectric device with a flexible photodetector to demonstrate this carrier collection approach in flexible/wearable electronics. To the best of our knowledge, this work is the first report of carrier extraction in organometallic halide perovskite photodetector by triboelectric charges, demonstrating a potential use for carrier extraction in other semiconductor-based optoeletronic devices.