Reflective type Solar-LCDs by using polarizing polymer solar cells.

We present herein the results of a study of the reflective polarizing photovoltaic (PV) effects in an aligned polymer bulk-heterojunction PV layer. The PV layer consisted of a composite of regioregular poly(3-hexylthiophene) and methanofullerene (P3HT:PCBM) and the fairly uniform in-plane alignment of the P3HT:PCBM PV layer was achieved by means of a simple rubbing technique. The macroscopic axial orientation of the P3HT polymer in the aligned PV layer was observed to be significantly increased in the direction of rubbing with an axial orientational order parameter of 0.40. Moreover, it was also found that the reflective polarizing polymer solar cells (PSCs) that contained the aligned P3HT:PCBM layers exhibited a greater degree of anisotropy of 1.60 for the PV efficiencies under polarized illumination along the two principal axes. These reflective polarizing PSCs were applied to new reflective type solar cell-liquid crystal displays (Solar-LCDs), which exhibited a contrast ratio of 1.7. These results form a promising foundation for various energy-harvesting polarization-dependent opto-electrical Solar-LCD device applications.