An interdisciplinary international team at Aalto University, University of Cambridge, Imperial College London and Beihang University have developed inks made of graphene-like materials for inkjet printing.
Black phosphorous is a particularly interesting nanomaterial, but despite its remarkable performance in the lab, practical real-world exploitation of this material has been hindered by complex material fabrication and its poor environmental stability.
The new black phosphorous inks are compatible with conventional inkjet printing techniques for optoelectronics and photonics.
"Our inkjet printing demonstration makes possible for the first time the scalable mass fabrication of black phosphorous based photonic and optoelectronic devices with long-term stability necessary for a wide range of industrial applications," said Professor Zhipei Sun at Aalto University in Finland.
The team optimised the chemical composition to achieve a stable ink through the balance of complex and competing fluidic effects.
This allowed them to demonstrate that black phosphorous ink can be seamlessly integrated with existing CMOS technologies. The controlled fabrication offered by the inkjet printing technique may also allow the fabrication of heterostructured materials that capitalise on the benefits of multiple nanomaterial layers.
They then demonstrated the benefits of their technique by inkjet printing devices that take advantage of the properties of black phosphorous, including its semiconducting bandgap that can be readily varied by engineering the number of atomic layers and can cover the visible and near-infrared region of the electromagnetic spectrum.
The researchers also demonstrated printed black phosphorous based nonlinear optical devices that can be easily inserted into lasers to act as ultra-quick optical shutters, converting a continuous beam of laser radiation into a repetitive series of very short bursts of light suited for industrial and medical applications, such as machining, imaging and sensing.
Black phosphorous was also able to act as an efficient and highly-responsive detector of light, extending the wavelength range over which conventional silicon-based photodetectors can operate.