Performance enhancement of polymer solar cells with luminescent down-shifting sensitizer

Enhanced performance of polymer solar cells is reported by incorporating a solution-processed luminescent down-shifting (LDS) sensitizer, which is composed of a C545T fluorescent molecule doped tris(8-quinolinolato) aluminum (C545T:Alq3). An optimized LDS sensitizer can result in ∼15% enhancement in power conversion efficiency than the reference device with pristine Alq3. The performance enhancement is associated with the increase in photocurrent induced by LDS sensitizer, which is capable of absorbing short-wavelength solar spectrum and re-emitting long-wavelength light, which is complementary with the absorption spectrum of the active layer. This method provides a facile approach for high-performance polymer solar cell designs.