Advancing the State of Knowledge
RFA3 will use the polymeric organic materials developed in RFA1 and RFA2 in systems with added inorganic components to introduce new properties such as prolonged excited-state lifetimes, prolonged photoinduced charge separation, and spin control. This RFA will probe how the use of progressively lower energy light will affect these properties. Many of these organic-inorganic systems are relatively well understood with small molecules and polymers absorbing visible light. However, in the NIR, SWIR, and MWIR regimes, these organic-inorganic interactions are not as well understood. As lower energy photons are used, significant changes in optical, spin, and charge separation properties are expected from these materials. The polymers being designed in RFA1 and RFA2 are uniquely well-suited to probe how changes in photon energy affect organic-inorganic materials heterostructure properties.
RFA3 will develop the fundamental chemistry, physics, materials science, and engineering to produce next-generation optoelectronic functionality and devices based on hybrid (organic-inorganic) heterostructures. The integration of organic semiconductors (OSCs) with tunable narrow bandgaps and unique electronic structures with inorganics will allow the rules that apply to matter and light to be further stretched, enable the design and realization of functions not available from the constituent materials, and seed completely new paradigms in optoelectronics. We will begin to elucidate the mechanisms governing the optical, transient, electronic, spin, magnetic, and correlated response arising from the interactions between the functional OSC and inorganic component. The properties of our materials can be controlled precisely, which has remained a persistent challenge for semiconducting materials with narrow bandgaps, such as carbon nanotubes (CNTs), 2D materials, transition metal dichalcogenides (TMDCs), colloidal quantum dots (CQD)s, inorganic nanocrystals (NCs), plasmonic nanoparticles (PNPs), perovskites, van der Waals heterostructures, and oxides. Research objectives and tasks (defined below) have been developed to address the following research questions:
3.1. How do we elucidate and control elementary excitations, dynamic processes, and electronic correlations at the complex interface between organic and inorganic materials?
3.2. How do OSC electronic, physical, and morphological features impact neutral and charged excitations at the interface of inorganic nanomaterials?
3.3. How do tailored covalent interfaces between OSCs and inorganic materials influence electronic coupling? How does interface composition affect properties?
3.4. How do OSC structural, electronic, physical, morphological, and transient properties affect charge separation and carrier transport in hybrid systems at progressively narrow bandgaps?
3.5. How do we control spin and manipulate the energies between open shell OSCs and inorganics? What new phenomena and properties are available and how can they be translated into devices?
Goals and Objectives
Goal 3: Establish design rules to guide dynamic processes at organic-inorganic interfaces with near-infrared and short wavelength infrared photons.
Objective 3.1: Make hybrid excitonic systems to generate organic-inorganic interfaces with materials optically active in the NIR or SWIR.
Objective 3.2: Transduce NIR and IR light in hybrid organic-inorganic systems into different forms of energy.
Objective 3.3: Establish theoretical approaches to predict complex interface induced phenomena and identify next generation target systems.
Objective 3.4: Design systems to generate long-lived photoinduced charge separation across NIR/SWIR absorbing organic-metal oxide interfaces.