Research Projects

The rapid miniaturization of electronic devices is approaching fundamental limits with conventional silicon-based technology. In this context, molecular electronics offers a transformative approach by utilizing individual molecules or molecular assemblies as functional electronic components. This project aims to uncover the structure–property relationships that govern charge and heat transport through both single-molecule and large-area molecular junctions, thereby establishing the foundational principles required for realizing next-generation nanoscale electronic, and thermoelectric,devices. The central hypothesis is that molecular structure, symmetry, redox states, interfacial chemistry, and external stimuli—such as electrochemical potential, light, magnetic field, temperature, and environment—can be precisely engineered to modulate charge transport and reactivity at the metal|molecule|metal interface. To test this hypothesis, we will employ a range of custom-built experimental platforms, including STM-based and mechanically controlled break junctions (MCBJ) for single-molecule studies and EGaIn-based setup for ensemble-level measurements. These platforms will be coupled with custom developed advanced measurement techniques such as differential conductance (dI/dV) analysis, inelastic electron tunneling spectroscopy (IETS), and thermoelectric transport (Seebeck coefficient) measurements. The scientific objectives of the project are as follows: Aim 1: Development of instruments for thermopower and charge transport measurements under the influence of external stimuli Aim 2: Development of instrumental and experimental methodology to measure Differential Conductance (dI/dV) and inelastic tunnelling spectroscopy (IETS) of the molecular junctions Aim 3: Demonstration of Field-modulated chemical reactivity and thermopower in molecular junctions Aim 4: Establishing the structure property relationships in “stimulus” responsive molecular junctions To realize these goals, we will employ a molecular design strategy where a central functional unit (F) is connected through spacer groups (S) and anchoring groups (A), in either symmetric (A–S–F–S–A) or asymmetric (A–S–F–S) configurations. These molecules will be integrated into hybrid metal|molecule|metal junctions using multiple platforms for method- and geometry-independent validation. Functional moieties will be embedded in the backbone or attached as pendant groups to explore switching, rectification, and transistor-like behavior under external fields. We will also establish an electrochemical surface-science-based approach at the nanoscale, enabling charge transport modulation via redox control, electric field gating, and environmental tuning. If successful, the project will deliver fundamental insights into quantum transport, nanoscale reactivity, and field-tunable functionality in molecular junctions. The ability to measure and control charge transport at the nanoscale will not only aid in the development of molecular switches, logic elements, and energy conversion devices but also impact broader fields such as molecular spintronics, catalysis, sensing, and photo/electrochemical energy conversion. Additionally, the development of indigenous experimental instrumentation will help build national capacity and innovation ecosystems in nanoscale science and quantum technologies, placing India at the forefront of experimental molecular electronics.