Inert-environment facilities for investigating optical-electrical-thermal properties of hybrid structure optoelectronics

Professor Choy, Wallace Chik Ho   (Principal Investigator (PI))

Dr Vellaisamy A. L. Roy   (Co-principal investigator)

Professor Wong Kam Sing   (Co-Investigator)

Dr Chan Kwok Leung   (Co-principal investigator)

Dr Sha Wei   (Co-principal investigator)

Dr Feng Shien Ping Tony   (Co-principal investigator)

36

2015-03-15

6107578

Inert-environment facilities for investigating optical-electrical-thermal properties of hybrid structure optoelectronics

functionalized metal oxide, integrated characterization, multiphysics, nanocomposite electrode, plasmonic nanostructure

Photonics,Materials Sciences

Engineering (E)

C7045-14E

Collaborative Research Fund (CRF) - Major Equipment Project

2014

Completed

1) Light managing in optoelectronic devices (e.g. solar cells need optically thick and physically thin and LEDs need strong light extraction). The incorporation of plasmonic metal nanostructures into device structures is believed to be the promising approach for addressing this issue. Besides the optical effects of the novel metal nanostructures, the metal nanostructure will modify the electrical properties (i.e. plasmonic-electrical effects) which are remaining unclear and important to be further investigated. The knowledge can contribute to the emerging plasmonic devices. Since the metal nanostructure incorporated material systems will be unexpectedly modified when exposes to air, the facilities are essential for investigating the nanoscale morphology, electrical and optical properties. 2) Efficient carrier transport between active layer and electrode. Functionalized metal oxides (e.g. MoOx, V2Ox, TiO2) with good electrical properties and stability are candidates for carrier-transporting layers. New approaches in synthesizing metal oxides with the unique features of low temperature, solution process (i.e. simple, low cost and scalable), water free (i.e. reduce water-induced device degradation) have been studied for tackling the challenge issues of low cost and large area applications. Metal nanomaterials, nanostructures and other dopants can be used to functionalize the metal oxides for effective electron and hole transportation. However, the intrinsic properties of these hybrid materials are still very difficult to be measured in air due to contamination. With the facilities in inert environment, the parameters (e.g. material, geometry, and concentration) of metal nanomaterials, nanostructures, metal oxide materials, and the morphology and electrical properties of metal/metal oxide systems can be studied for achieving a new class of functionalized metal oxides for optoelectronic applications. 3) Hybrid material systems for flexible electrodes. Flexible optoelectronics are the emerging technologies in advancing new applications. It is desirable to develop novel hybrid material systems for flexible electrode. The hybrid structures of graphene hybridized with metal nanomaterials and metal oxides are potential candidates for low-cost flexible electrodes. Besides, bilayer electrode composed of an inner metal-oxide nanoparticle (NP) matrix covered with a thin layer of large-bandgap metal oxides or polymers can be studied for addressing the surface recombination issues around metaloxide NPs and improving the electrical properties. Since the surface properties (e.g. surface potential and workfunction) of the nano-hybrid structures are very sensitive to the environment, the proposed facilities are very important for fabricating and characterizing the hybrid structures. 4) Thermal management of hybrid structure optoelectronics. Apart from the optical and electrical effects as stated in above Objectives, the metal nanostructures incorporated in a material system (e.g. organic and metal oxides) will affect the heat generation and dissipation paths which will also influence the optoelectronic properties. Hybrid thin films such as metal/graphene, and metal oxide/organic will have different thermal properties due to the extra heat carrier scattering in the interface between two materials, and such thermal boundary resistance would hinder the heat conduction. Thermoreflectance will be used to investigate the thermal conductivity of the hybrid thin films with different nanostructure sizes and concentrations. Besides, the heat generation due to electron-phonon scattering in composite thin films will also be studied by thermal scanning microscopy under nitrogen environment. 5) Comprehensive understanding of device physics. Multiphysics (optical, electrical and thermal) models will be developed to study the origins and new physics of hybrid material systems. With the experimental results in above Objectives, we can understand the fundamental physics and contribute to innovate new optoelectronics using the hybrid material systems. 6) Through the project, we can promote collaborative research among professionals with multidisciplinary backgrounds from institutions and industries.