Schottky junction based solar cell behavior of trichome hierarchical SnO2 nano-structures

Hydrothermally grown SnO2 hierarchical trichome nano-flowers (T-NFLs) have been examined for their device performance compared to nano-flakes (NFs), in part to meet the growing need for metal-oxide based solar cells. The structural analyses reveal superior lattice strain and free energy in the tetragonal phase of the T-NFLs over NFs. The band gap widening and oxygen defect-dominated luminescence in the visible range are observed from photoluminescence measurements. Compared to NFs, the Schottky current-voltage characteristics of the T-NFLs show improved Schottky barrier height (0.82 eV) with an ideality factor of 3.52 under dark and better solar cell properties with a conversion efficiency of 1.78 +/- 0.03% under 1 sun illumination. The observed high open-circuit voltage of 1.56 V resulted from the decrement rate of carrier recombination, making the transparent metal oxide nano-material SnO2 T-NFLs suitable for solar cells and fast electronic applications.