TY - JOUR
T1 - Thermally driven reversible photoluminescence modulation in WS 2 /VO 2 heterostructure
AU - Kumar, Pawan
AU - Singh, Davinder
AU - Balakrishnan, Viswanath
N1 - Publisher Copyright:
© 2019 Elsevier B.V.
PY - 2019/6/30
Y1 - 2019/6/30
N2 - We demonstrate reversible modulation of photoluminescence in chemical vapor deposition (CVD) grown WS 2 monolayer transferred on VO 2 thin films that undergo insulator-metal transition. Thermally driven phase transition in VO 2 thin film involving structural change as well as thermal expansion mismatch at interfaces induce strain and able to reversibly tune photoluminescence (PL) of atomic thin WS 2 layer. PL intensity is increased with enhancement factor of 1.83 which corresponds to ~250% enhancement when heated from 30 °C to 70 °C. With further increase of temperature, PL intensity is found to be decreasing due to thermal quenching. While interference effect arising from metallic VO 2 /WS 2 interface may also contribute for luminescence enhancement in metallic state, the observed increase in photoluminescence intensity during heating within the insulating state reveals the role of thermal strain. Systematic in-situ Raman and PL measurements revealed role of phase transition in controlling the PL intensity of excitons in WS 2 monolayer. Single crystalline VO 2 microplates also have been used to confirm the PL intensity modulation across phase transition. The observed direct correlation between photoluminescence and phase change interaction of VO 2 with atomic thin layer of WS 2 provide novel platform to tune the optical properties for diverse smart photonic applications.
AB - We demonstrate reversible modulation of photoluminescence in chemical vapor deposition (CVD) grown WS 2 monolayer transferred on VO 2 thin films that undergo insulator-metal transition. Thermally driven phase transition in VO 2 thin film involving structural change as well as thermal expansion mismatch at interfaces induce strain and able to reversibly tune photoluminescence (PL) of atomic thin WS 2 layer. PL intensity is increased with enhancement factor of 1.83 which corresponds to ~250% enhancement when heated from 30 °C to 70 °C. With further increase of temperature, PL intensity is found to be decreasing due to thermal quenching. While interference effect arising from metallic VO 2 /WS 2 interface may also contribute for luminescence enhancement in metallic state, the observed increase in photoluminescence intensity during heating within the insulating state reveals the role of thermal strain. Systematic in-situ Raman and PL measurements revealed role of phase transition in controlling the PL intensity of excitons in WS 2 monolayer. Single crystalline VO 2 microplates also have been used to confirm the PL intensity modulation across phase transition. The observed direct correlation between photoluminescence and phase change interaction of VO 2 with atomic thin layer of WS 2 provide novel platform to tune the optical properties for diverse smart photonic applications.
KW - In-situ temperature effect
KW - Monolayer WS
KW - Reversible PL modulation
KW - Surfaces and interfaces
KW - VO thin film heterostructure
UR - https://www.scopus.com/pages/publications/85062469521
U2 - 10.1016/j.apsusc.2019.03.033
DO - 10.1016/j.apsusc.2019.03.033
M3 - Article
AN - SCOPUS:85062469521
SN - 0169-4332
VL - 480
SP - 680
EP - 688
JO - Applied Surface Science
JF - Applied Surface Science
ER -