Fig. 1. (Color online) (a) Schematic illustration of the Ti₃C₂T_x MXene. (b) Schematic diagram showing the typical photolithography process to prepare the patterned Ti₃C₂T_x microelectrode. The inset is the digital photograph of the synthesized Ti₃C₂T_x MXene suspension. (c) Digital photograph of the 2 × 2 cm² square patterned Ti₃C₂T_x microelectrode array on flexible PET substrate. (d, e) AFM images show the thickness and surface morphology of the Ti₃C₂T_x MXene. (f) TEM image of the prepared ZnSb nanoplate. (g, h) TEM images and EDS mapping of an individual ZnSb nanoplate. (i) HRTEM image of the ZnSb. (j) Elemental spectrum of the ZnSb nanoplates. (k) XRD patterns of the Ti₃C₂T_x MXene.

Fig. 2. (Color online) (a) Schematic of the ZnSb/Ti₃C₂T_x MXene PDs. (b) Photocurrent of ZnSb/Ti₃C₂T_x MXene PDs irradiated by laser with different wavelengths. (c) I−V curves of the ZnSb/Ti₃C₂T_x MXene PDs under dark and laser irradiation with different wavelengths. (d) I−T curves of the fabricated PD devices to laser irradiation with various wavelengths ranging from 915 to 2200 nm. (e, f) Photocurrent and on/off ratio of ZnSb/Ti₃C₂T_x MXene PDs irradiated by laser with different optical power densities at 1342 nm. (g) I−V characteristics of the ZnSb/Ti₃C₂T_x MXene PDs to 1342 nm incident laser at increased laser densities varying from 15.9 to 178 mW/cm².

Fig. 3. (Color online) (a) Microscope images of the prepared ZnSb/Ti₃C₂T_x MXene PD devices. (b) Crystal structure of the ZnSb nanoplates with orthorhombic forms. (c) Photoresponsivity and detectivity curves of the PD devices to laser irradiation of different wavelengths varying from 915 to 2200 nm. (d, e) Photoresponsivity, detectivity and EQE curves of the PD devices to 1342 nm laser irradiation with different light intensity. (f) Response and recovery time of the fabricated ZnSb/Ti₃C₂T_x MXene PD devices. (g) ZnSb molecular structure model for bandgap calculation. (h) Energy band width and density of States diagram of ZnSb. (i) Energy band diagram of ZnSb in contact with Ti₃C₂T_x MXene.

Fig. 4. (Color online) (a) Digital image of the fabricated PD arrays under bending states. (b) I_on/I_off variation of the ZnSb/Ti₃C₂T_x MXene PDs under different bending states. (c) I−T curves of the flexible devices under 1342 nm illumination after 5000 cycles of bending. (d) Schematic illustrations showing the measurement method of the PD devices to sense the words "MXene". (e) I_on/I_off variation of the 26 × 5 ZnSb/Ti₃C₂T_x MXene PD arrays through a light mask of "MXene".