SYNTHESIS AND ASSEMBLY OF 1D INORGANIC SEMICONDUCTOR FOR SOLAR ENERGY CONVERSION

摘要

Nanoscale inorganic semiconductors have become promising low-cost high surface area electrode materials for solar cell and solar fuel productions. Charge transport within electrode materials is a major determinant of these device performances. However, high surface area electrode is normally associated with small size of randomly packed nanoparticles (NPs) and exhibits significantly low electron mobility. To address these challenges, (1) we fabricated ordered single-crystal 1D TiO2 nanowire (NW) arrays and first demonstrated that their electron transport is 200-fold higher than that in NP films. (2) Although 1D NW arrays have marked improved electron transport, the large volume of free space between NWs limits its surface area. We have reported the fabrication of oriented assembled TiO2 hierarchical nanoarrays consisting of 1D branch epitaxially grown from the primary trunk. The 3D NW arrays show 71% higher surface area related to 1D NW arrays, which leads to 52% improvement in solar convention efficiency without affecting electron collection2. (3) To further increase the surface area, we fabricated [10-10] oriented ZnO NW arrays with multichannel structure. The NW exhibits 2-3 orders of magnitude faster electron transport rate than that in NP films. Moreover, the surface area of the as-prepared NW arrays is comparable to that of commonly used NP films3. The high surface area and rapid charge transport properties make these NW arrays ideal electrode structures for future various optoelectronic device applications.