| 초록 |
We report a powerful strategy for retarding back electron transfer (BET) by controlling both the photoelectrode thickness and π-spacer dihedral angle. A results show that twisted π-spacers were more efficient at retarding BET than the planar π-spacer. However, BET was found to be less important than expected, and light harvesting efficiency (LHE) played a critical role as the thickness of the photoelectrode decreased because charge collection efficiency was enhanced. The planar dye BT-T obtained the highest LHE, this value remained unusually high even in 1.8 μm photoelectrodes. As a result, BT-T gave a PCE of 6.5% in thin 1.8 μm photoelectrodes with 3.5 μm scattering layers, which represented a roughly 40% enhancement compared to the PCE in 10 μm photoelectrodes (4.76%). |
