Kim, Sunkook Maassen, Jesse Lee, Jiyoul Kim, Seung Min Han, Gyuchull Kwon, Junyeon Hong, Seongin Park, Jozeph Liu, Na Park, Yun Chang Omkaram, Inturu Rhyee, Jong-Soo Hong, Young Ki Yoon, Youngki 2024-01-19T23:03:48Z 2024-01-19T23:03:48Z 2021-09-03 2018-03-22 0935-9648 https://pubs.kist.re.kr/handle/201004/121588 Thin-film transistors (TFTs) based on multilayer molybdenum diselenide (MoSe2) synthesized by modified atmospheric pressure chemical vapor deposition (APCVD) exhibit outstanding photoresponsivity (103.1 A W-1), while it is generally believed that optical response of multilayer transition metal dichalcogenides (TMDs) is significantly limited due to their indirect bandgap and inefficient photoexcitation process. Here, the fundamental origin of such a high photoresponsivity in the synthesized multilayer MoSe2 TFTs is sought. A unique structural characteristic of the APCVD-grown MoSe2 is observed, in which interstitial Mo atoms exist between basal planes, unlike usual 2H phase TMDs. Density functional theory calculations and photoinduced transfer characteristics reveal that such interstitial Mo atoms form photoreactive electronic states in the bandgap. Models indicate that huge photoamplification is attributed to trapped holes in subgap states, resulting in a significant photovoltaic effect. In this study, the fundamental origin of high responsivity with synthetic MoSe2 phototransistors is identified, suggesting a novel route to high-performance, multifunctional 2D material devices for future wearable sensor applications. English WILEY-V C H VERLAG GMBH TOTAL-ENERGY CALCULATIONS THIN-FILM TRANSISTORS MOBILITY TRANSISTORS LARGE-AREA TRANSITION PHOTOCONDUCTIVITY MECHANISMS BANDGAP Interstitial Mo-Assisted Photovoltaic Effect in Multilayer MoSe2 Phototransistors Article 10.1002/adma.201705542 1 ADVANCED MATERIALS, v.30, no.12 ADVANCED MATERIALS 30 12 scie scopus 000428348000009 2-s2.0-85041093354 Chemistry, Multidisciplinary Chemistry, Physical Nanoscience & Nanotechnology Materials Science, Multidisciplinary Physics, Applied Physics, Condensed Matter Chemistry Science & Technology - Other Topics Materials Science Physics Article TOTAL-ENERGY CALCULATIONS THIN-FILM TRANSISTORS MOBILITY TRANSISTORS LARGE-AREA TRANSITION PHOTOCONDUCTIVITY MECHANISMS BANDGAP 2D materials interstitial effects MoSe2 phototransistors photovoltaics