Bio-inspired transparent MXene electrodes for flexible UV photodetectors†
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.