Organic solar cells based on acceptor-functionalized diketopyrrolopyrrole derivatives

Abstract

Abstract. The synthesis and characterization of three solution processable diketopyrrolopyrrole (DPP) derivatives featuring acceptor units attached to the core by alkyne linker units is reported. Cyclic voltammetry and density functional theory calculations indicate that the DPP derivatives possess similar HOMO and LUMO energies. Solar cells were fabricated by blending the synthesized DPP derivatives with [6,6]-phenyl-C71-butyrate methyl ester. The influence of donor: acceptor blend ratio, film thickness, annealing temperature, and annealing time on device performance was studied. Differences in device performance were related to atomic force microscopy measurements of the films. The highest power conversion efficiency of 1.76% was achieved for the DPP derivative functionalized with an aldehyde electron-withdrawing group with a 1∶0.7 donor:acceptor ratio when the active layer was annealed for 10 min at 110°C.

Polyethylenimine-Ethoxylated Interfacial Layer for Efficient Electron Collection in SnO2-Based Inverted Organic Solar Cells

“…Third-generation photovoltaic technology based on conjugated polymers has drawn much attention over the past decade due to advantages such as simple preparation, light weight, low cost, solution-based fabrication on large-area and low-temperature solution process ability that allows for fabrication on flexible substrates via roll-to-roll manufacturing for solar energy conversion [1][2][3][4]. Recently, efforts have been made to enhance power conversion efficiency (PCE) of organic solar cells (OSCs), reaching a power conversion efficiency above 15-17% [5,6].…”

Significance of light-soaking effect in proper analysis of degradation dynamics of organic solar cells

“…During the degradation process, trap states and defects are created due to different paths of degradation, e.g., photooxidation, diffusion of atoms, reorganization of BHJ, and many others. [32][33][34][35][36][37] Some of these trap states, close to the ITO/ZnO, could be filled up during the light-soaking illumination. 19,22 On the other hand, the trap states, close to the ZnO/P3HT:PCBM, could change the induced interfacial dipoles.…”