Synthesis of continuous MoS2:Er films and their enhanced NIR photoresponse for photo communication

摘要

Enhancing the near-infrared (NIR) photoresponse of molybdenum disulfide (MoS2) is essential for its photoelectric applications including photo communication. Herein, continuous Er-doped MoS2 (MoS2:Er) films were synthesized via a multi-step process. The enhanced NIR response of MoS2:Er at 808 nm and 980 nm is attributed to the characteristic absorption of Er3+ at both wavelengths and the increased traps introduced by Er-doping. The developed MoS2:Er/SiO2/p-Si heterojunction device possesses a rapid response time of & SIM;1.4 & mu;s, a high detectivity of & SIM;3.67 x 10(10) Jones, and a wide 3 dB bandwidth of 7.9 kHz at -0.5 V under 980 nm laser irradiation. The dark current of the heterojunction photodetector can be suppressed under 980 nm laser illumination for a period longer than 8 ms because of an extra light-generated field in the dark induced by the residual charges in the traps. Meanwhile, a NIR light communication system is demonstrated by employing the heterojunction detectors as the receiver. This work provides an alternative method to synthesize homogeneous metal-doped MoS2 films and an effective strategy to modulate the photoelectric performance of MoS2-based devices.

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