Luminescent Sm-doped aluminosilicate glass as a substrate for enhanced photoresponsivity of MoS2 based photodetector

Abstract

© 2021 Elsevier B.V.The choice of substrate is crucial for device applications, in particular for atomically thin materials such as monolayer transition metal dichalcogenides. The interaction between the active material and the substrate could be exploited to improve the device performance. In this work, we used a Sm-doped aluminosilicate glass (Sm-ASG) as a substrate for monolayer MoS2 based photodetector. Due to the strong high-energy emission lines of Sm, Sm-ASG substrate absorbs the incident light and acts as second excitation source compensating the low absorption of the MoS2 monolayer. On Sm-ASG substrate, the MoS2 photoresponsivity was increased up to 13,157 AW−1 as compared to 5,740 AW−1 on undoped ASG substrate, under illumination of a monochromatic laser with 520 nm wavelength at a power of 0.2 µW. The significantly enhanced photoresponse, which is amongst the highest reported values for unbiased photoconductors, is attributed to the dual function of Sm-ASG substrate, consisting of a surface charge transfer and an enhanced photoexcitation via a photon recycling effect. Our new approach, based on the simple use of substrate, paves the way for achieving high performance optoelectronic devices.