Currently, polymer solar cells are far behind the conventional silicon solar cells. However, as thrusts for green energy continue, the relative low cost of the polymer solar cells could play a big role, and the huge jumps these cells are making in terms of efficiency only makes things better for them. A recently developed nano-patterned array production technique showed researchers a seven-fold increase in efficiency as compared to the conventional sandwich-style construction.
Solar cells basically work through a system of electron donor and acceptor layers. These layers are only a few nanometers thick, and were optimized by researchers for this study. P3HT, the electron donor part of the cell, was patterned by aluminum oxide and drawn into honeycomb like arrays. The P3HT was a mere 30nm thick, and had pillars 150nm tall and 75nm thick running through the structure.
The polymer chains greatly increased the conductivity of the structure, and with a higher interfacial yield, the efficiency increased by nearly 7 times, or more specifically, 6.6 times. There is still a long way to go though, even with that jump in efficiency, the absolute efficiency of the array is a mere 1.12%, but it may open up new roads.