SearcharxivSearch

arXiv subjects

Harikrishnan G.

Publications and source records attributed to Harikrishnan G..

2 recordsLinked to original sources

Photo-thermoelectrics of a distributed Schottky junction system: Delineating the photo and thermal currents

Hybrid materials, consisting of diverse materials combined in various configurations, exhibit intriguing opto-electronic properties and are a focal point of research in functional materials. However, achieving precise predictability and tunability of their macroscopic properties in terms of the control parameters remains a challenge. One promising approach involves leveraging self-organization through eutectic growth and subsequent engineering via annealing to engineer niche properties. Here, the electronic properties of eutectic NiTiO$_3$-TiO$_2$ samples and their H$_2$-reduced counterpart Ni-TiO$_2$ are investigated, where the latter features high aspect ratio TiO$_2$ nanostructures decorated with nodular Ni globules. By exploiting this unique architecture and capitalizing on the nanostructuring processes alongside material properties, performance enhancement of photoactive devices is shown. Further, the competing mechanisms of photo-driven and photo-thermal-driven transport is delineated to characterize the overall photo-response of the system. The ability for self-powered functionality further showcases this approach as a promising strategy for developing efficient self-powered devices.

physics.app-ph

Mobility enhancement in CVD-grown monolayer MoS2 via patterned substrate induced non-uniform straining

The extraordinary mechanical properties of 2D TMDCs make them ideal candidates for investigating strain-induced control of various physical properties. Here we explore the role of non-uniform strain in modulating optical, electronic and transport properties of semiconducting, chemical vapour deposited monolayer MoS2, on periodically nanostructured substrates. A combination of spatially resolved spectroscopic and electronic properties explore and quantify the differential strain distribution and carrier density on a monolayer, as it conformally drapes over the periodic nanostructures. The observed accumulation in electron density at the strained regions is supported by theoretical calculations which form the likely basis for the ensuing 60x increase in field effect mobility in strained samples. Though spatially non-uniform, the pattern induced strain is shown to be readily controlled by changing the periodicity of the nanostructures thus providing a robust yet useful macroscopic control on strain and mobility in these systems.

cond-mat.mtrl-sci