Donor Acceptor Molecular Systems for Electron Transfer
Donor-acceptor (D-A) systems (in configurations such as D-A-D, A-D-A, D-A-A etc.) will be designed and synthesized for efficient photoinduced electron transfer (PET). Major emphasis will be given on their photophysics, charge carrier mobilities and electronic properties in order to assess their suitability in photoconduction for their incorporation in OPV devices.
Fig 1. An example of two regioisomeric donor-acceptor-donor triads showing efficient electron transfer and charge carrier mobilities.
Fig 2. Spectral overlap of energy acceptor (SQ) absorption and donor (D-BDP-D & Ph-BDP-Ph) emission of two subchromophoric molecules developed recently in this group for FRET.
Excitation Energy Transfer
Covalently connected multichromophoric systems (based on squaraine, DPP, rylenes, BODIPY, isoindigo and few other classes of molecules with complementary absorption) will be developed with the aim of achieving efficient Förster resonance energy transfer (FRET). Design strategies would involve the use of dendritic structures where different chromophores can be positioned with favorable orientations for FRET. Eventual aim would be to achieve enhanced OPV performances compared to conventional donor-acceptor blends.
Twisted D-A Systems
Covalently connected D-A systems with variable spacer unit(s) will be designed for twisted intramolecular charge transfer (TICT), aggregate induced emission (AIE) and/or thermally activated delayed fluorescence (TADF). Fundamental structure-property relationships of these materials will be deduced through structural and optical characterization. Eventually, the application of some of the screened materials in fabrication of organic light emitting diodes (OLEDs) will be explored.
Overview of Research Activities
Fig 3. An example of a twisted D-A triad system showing efficient fluorescence solvatochromism as a result of formation of a TICT state.
Methodologies
