High-Efficiency Blended Heterojunction Organic Solar Cell with Enhanced PCE Using PCDTBT: PCBM Absorber Layer

This work rigorously explores a Blended Heterojunction (BHJ) Organic Solar Cell (OSC) using a blend of Donor/Acceptor (D/A) fullerene polymers (PCDTBT and PCBM) as the photoactive absorber layer. The proposed OSC has been implemented and modeled using the ATLAS tool of Silvaco TCAD, a widely used commercial software. The thin heterojunction photoactive absorber layer of blended PCDTBT: PCBM D/A polymers increase the diffusion length causing a significant reduction in the Langevin recombination and hence, enhance the Power Conversion Efficiency (PCE). The hole transport is enhanced by a thin layer of PEDOT: PSS, an organic blended polymer. As anode and cathode, Indium Tin Oxide (ITO), a transparent conductive oxide, and Aluminum (Al) are used. The modeling of the OSC has considered the effects of singlet dissociation and recombination, and the Langevin recombination for accuracy and better physical insight. The electrical simulations of the proposed OSC carried out in the Silvaco environment resulted in improved current-voltage characteristics, which demonstrate a high open circuit voltage (0.965 V), an impressive fill factor (66.717%), a moderate short circuit current density (10.505 mA/cm2), and an enhanced PCE (6.766%). The optical simulations of the proposed OSC demonstrate its external quantum efficiency of more than 25% over the wavelength span of 380–1500 nm.