Mechanisms of photoconductivity in atomically thin MoS2.

By Marco M. Furchi, Dmitry K. Polyushkin, A. Pospischil, Thomas Mueller. Nano letters (Print), 2014

626 citations recorded by the source corpus.

Atomically thin transition metal dichalcogenides have emerged as promising candidates for sensitive photodetection. Here, we report a photoconductivity study of biased mono- and bilayer molybdenum disulfide field-effect transistors. We identify photovoltaic and photoconductive effects, which both show strong photogain. The photovoltaic effect is described as a shift in transistor threshold voltage due to charge transfer from the channel to nearby molecules, including SiO2 surface-bound water. The photoconductive effect is attributed to the trapping of carriers in band tail states in the molybdenum disulfide itself. A simple model is presented that reproduces our experimental observations, such as the dependence on incident optical power and gate voltage. Our findings offer design and engineering strategies for atomically thin molybdenum disulfide photodetectors, and we anticipate that the results are generalizable to other transition metal dichalcogenides as well.

Subfields: Atomic and Molecular Physics, and Optics, Materials Chemistry

View Paper: https://www.semanticscholar.org/paper/8b3302795e2f76e64caaaddf744bb9b760b6bff5

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Atomic and Molecular Physics, and Optics

1. Filippo Giubileo
2. A. Di Bartolomeo
3. Fengnian Xia
4. E. Malic

In Materials Chemistry

1. A. Di Bartolomeo
2. Filippo Giubileo
3. Fengnian Xia
4. E. Malic
5. Giuseppe Luongo
6. Thomas Mueller
7. L. Iemmo
8. Han Wang

Citations in the corpus

• Optoelectronic devices based on two-dimensional transition metal dichalcogenides (2016, background): “[79] revealed that the photoconductive gain in MoS2 stems from the trapping of either the electrons or holes, which yields prolonged photocarrier lifetime and in turn high photoconductive gain.”
• Hysteresis in the transfer characteristics of MoS2 transistors (2017, background): “band-tail states of MoS2 [22, 23], while extrinsic causes include photocharge trapping in residues and adsorb-”
• Exciton physics and device application of two-dimensional transition metal dichalcogenide semiconductors (2018, background): “In a field-effect transistor, the trapped charge not only increases the channel conductance but also shifts the transistor’s threshold voltage [146].”