Bio-inspired transparent MXene electrodes for flexible UV photodetectors

Abstract

2D transition metal carbides (MXenes) have emerged as one of the representative materials for transparent electrodes of electronics, but it is still a challenge to achieve highly transparent and conductive MXene electrodes for flexible photodetectors due to the tradeoff between resistance and transmittance. Herein, we put forward a bio-inspired transparent MXene film with a high transmittance of about 90% and low sheet resistance value of around 3 Ω sq⁻¹. Moreover, thanks to the presence of various surface terminal groups, the MXene electrode's work function is adjustable via different etching processes, and in conjunction with electrospun TiO₂ films a semi-transparent UV photodetector is integrated. Furthermore, the electrode and the constructed photodetector both exhibit superb flexibility which can survive 1000 bending cycles. This work not only provides a novel pathway to simultaneously improve the transmittance and conductivity of transparent electrodes, but also is available for extensive applications of optoelectronics.