Tuning optoelectronic properties in nanomaterials for exploitation of solar radiation
Our goal is to investigate new inorganic materials for solar thermal energy conversion and gain an understanding of fundamental mechanisms at the interface. We study a diversity of 2D, and 3D inorganic black materials which can be used as highly efficient selective solar absorbers and as membranes with relevant solar-water evaporation performance under solar irradiation.
Over the past decades, renewable energy harvesting from the sun has inspired a variety of investigations related to the resolution of escalating energy crisis. In our study, we are working on two different applications of inorganic black materials.
Firstly, the interfacial solar vapor generation (SVG) field has great importance among recently developed technologies for secure fresh water supply. The selection of the photothermal absorber layer plays a key role in evaporation performance. The sunlight illumination on to select absorber layer raises the surface temperature, which then converts water into vapors. Nowadays, the most reported value of SVG is 1.25 kgm-2·h-1, that still not enough to use the technology under commercial-relevant conditions. Broad solar absorption in the sun irradiation range allows full utilization of the entire available solar energy, while efficient water transport ensures consistent water supply to the evaporator.
Secondly, inorganic materials possessing high surface temperature under solar illumination are valuable for a wide range of applications such as passive heating, thermoelectricity generation, anti-icing/deicing, and solar water evaporation. The significant impediment to obtaining a surface temperature higher than 100 °C is massive thermal re-radiation under illumination which prevents heat concentration within the absorber and as a result, its surface temperature reduces drastically. Therefore we are working on the development of inorganic systems exhibiting wide broad solar absorption and simultaneous owing negligible thermal re-radiation back to the environment in the mid-infrared region.
The main inorganic black material for applications in renewable energy we are currently targeting are CoSb3, SnSe, Ni-Co selenites, and CuS. In all materials, our goal is to essential to understand the relationship between the intrinsic optical properties and physical performance. Our main laboratory-based techniques include SVG test, X-ray diffraction to access structural analysis, X-ray photoelectron spectroscopy to determine the surface chemistry/composition, scanning electron microscopy to investigate the morphology, and Fourier-transform infrared spectroscopy for characterization of optical properties. Here, the most urgent question is to investigate the new inorganic black materials for potential use as highly efficient intrinsic select solar absorbers and as the photothermal layer with high SVG performance under solar irradiation.