Substitutionally Doped MoSe2 for High-Performance Electronics and Optoelectronics

2D materials, of which the carrier type and concentration are easily tuned, show tremendous superiority in electronic and optoelectronic applications. However, the achievements are still quite far away from practical applications. Much more effort should be made to further improve their performance. Here, p-type MoSe2 is successfully achieved via substitutional doping of Ta atoms, which is confirmed experimentally and theoretically, and outstanding homojunction photodetectors and inverters are fabricated. MoSe2 p-n homojunction device with a low reverse current (300 pA) exhibits a high rectification ratio (10(4)). The analysis of dark current reveals the domination of the Shockley-Read-Hall (SRH) and band-to-band tunneling (BTB) current. The homojunction photodetector exhibits a large open-circuit voltage (0.68 V) and short-circuit currents (1 mu A), which is suitable for micro-solar cells. Furthermore, it possesses outstanding responsivity (0.28 A W-1), large external quantum efficiency (42%), and a high signal-to-noise ratio (approximate to 10(7)). Benefiting from the continuous energy band of homojunction, the response speed reaches up to 20 mu s. Besides, the Ta-doped MoSe2 inverter exhibits a high voltage gain (34) and low power consumption (127 nW). This work lays a foundation for the practical application of 2D material devices.

Automated summary

2D materials, with easily tunable carrier type and concentration, show great potential in electronic and optoelectronic applications, but still require further improvement for practical use. Through substitutional doping of Ta atoms, p-type MoSe2 was successfully achieved, leading to the fabrication of outstanding homojunction photodetectors and inverters. The devices demonstrate high rectification ratio, large open-circuit voltage, and exceptional responsivity and efficiency, laying a foundation for the practical application of 2D material devices.