Fernando Rodríguez-Mas

The efficiency of organic solar cells (OSCs) is strongly governed by energetic disorder within charge transport layers. In this work, we investigate how secondary solvent additives (DMF, THF, and DMSO) affect hole transport in PEDOT:PSS-based devices. Rather than relying on single-carrier architectures, we apply the Space-Charge-Limited Current (SCLC) formalism directly to complete photovoltaic devices, enabling in-situ extraction of effective mobility and trap distributions under realistic operating conditions. An optimized THF treatment increases power conversion efficiency by 51.4%, outperforming both reference devices and those treated with DMSO or DMF. Physical analysis reveals that this improvement does not arise from a reduction in total trap density, but from a mitigation of energetic disorder, quantitatively evidenced by a decrease in characteristic trap energy from 98 meV in the reference device to 85 meV in the optimized THF-treated cell, accompanied by an increase in effective mobility. Conversely, excessive DMSO incorporation leads to deeper trap distributions exceeding 110–140 meV, severely constraining charge transport despite moderate reductions in series resistance. These results demonstrate that hole transport and photovoltaic performance in PEDOT:PSS-based organic solar cells are governed primarily by the energetic distribution of trap states rather than by their absolute density.

We report the enhancement of organic photodetector (OPD) performance through the incorporation of CsPbBr₃ perovskite nanocrystals (PNCs) into P3HT:PCBM devices. The optimized device (HPD_01) exhibits a maximum responsivity of 0.083 A/W and a specific detectivity of ~4.7 × 10¹⁰ Jones, and a minimum NEP of 5.2 × 10⁻¹² W·Hz^−1/2 at the self-powered operating point (V ≈ 0 V), outperforming the nanoparticle-free reference. Frequency- and distance-dependent measurements under visible light communication conditions demonstrate that the optimized device maintains strong signal detection up to 1 MHz and at distances exceeding 15 cm. Notably, the external quantum efficiency spectra reveal an additional contribution in the 450–575 nm range, which is absent in the reference device. This enhancement is consistent with a radiative absorption–reemission energy-transfer mechanism, supported by quantitative spectral overlap analysis showing that 99.5% of the PNC photoluminescence falls within the 450–575 nm EQE enhancement window and that the maximum differential EQE gain occurs at 519 nm—only 2 nm from the PNC emission peak. Our results suggest that controlled PNC incorporation enables efficient optical energy coupling, leading to high-sensitivity, fast-response OPDs suitable for optical communication applications.

Organic solar cells (OSCs), especially those employing bulk heterojunction architecture, present a promising avenue in renewable energy technology. These devices utilize organic materials and can be doped by solvents such as dimethylformamide (DMF), tetrahydrofuran (THF), and dimethyl sulfoxide (DMSO). Solvent doping (DMF, THF, and DMSO) is observed to augment the efficiency of OSCs. However, a trade‐off exists between the volume of solvent used and the device's efficiency. The judicious selection of solvents is crucial as it directly impacts the environmental footprint of the fabrication process and the power conversion efficiency. Notably, the use of solvents in OSC fabrication contributes to reducing the environmental impact across various categories, in particular Abiotic Depletion, Global Warming, and Human Toxicity. Among the solvents studied, THF demonstrates the most significant reduction in environmental impact. Therefore, optimizing the choice and volume of solvents in OSC fabrication is paramount for achieving both enhanced device performance and minimal environmental footprint.