Figure 8

Characterization of Co-DNA-doped TMD photodetectors under laser exposure with different wavelengths.

(a) I_D−V_G characteristics of MoS₂ and WSe₂ photodetectors doped by Gd³⁺-based Co-DNA under laser exposure with different wavelengths (655, 785 and 850 nm). (b) Energy band structures of bulk MoS₂ and WSe₂. Here, we approximately marked the photon or phonon transition under the laser exposure with different wavelengths. (c) Photoresponsivity ratio (R_Co-DNA/R_Control) and (d) detectivity ratio (D*_Co-DNA/D*_Control) of Gd³⁺ and Tb³⁺-based Co-DNA-doped TMD photodetector under different laser exposures. (e) Photoluminescence data of DNA and Tb³⁺-DNA crystals and Gaussian fitting lines for Tb³⁺-DNA PL data. Here, the excitation wavelength is 400 nm. (f) Energy state levels of Tb³⁺-DNA and the schematic presenting the mechanism of photocarrier transfer from Tb³⁺ ions to the TMD.