Diffusion-enhanced exciton dissociation in single-material organic solar cells

Abstract

Single-material organic solar cells have recently come to the research spotlight due to their simplicity, morphological robustness and high yield of exciton dissociation. Using α-sexithiophene as a model system, we...

Wearable in-sensor reservoir computing using optoelectronic polymers with through-space charge-transport characteristics for multi-task learning

“…To this end, we adopt a semiconductor configuration in which the molecular π-planes are stringed together on a non-conjugated polymer backbone with a well-defined interval distance. Theoretically, the flexible polymer backbone (1) prevents long-range ordering of molecular π-planes but leads to short-range ordered domains with different molecular orientations, which generates an electrostatic landscape with an interfacial energy offset, and facilitates exciton dissociation and charge separation 53 , 54 . Such a feature is critical to achieving a nearly-linear and continuous response to light irradiation, rather than a fast-saturated photocurrent response that is typically observed in conventional semiconductors (e.g., P3HT and pentacene).…”

“…3i ). Such a high degree of disordering generates an electrostatic landscape with an interfacial energy offset at the boundaries between p -NDI coils, which promotes the formation of hybridized exciton/charge-transfer states at the interface, resulting in an efficient exciton dissociation into free charges 53 , 54 . In addition to the diffraction arcs along q xy direction, the presence of two bright short arcs along q z direction reveals a high degree of out-of-plane ordering.…”

Phase modulated scanning near field optical luminescence imaging as a probe of exciton dark lifetime and diffusivity in persistently luminescent micro- and nanocrystals

“…Table 1 assesses the resolution, both spatial (lateral) and in the time domain of different techniques normally used to determine the exciton diffusion length in optical materials and nanomaterials. A significant advantage of PM-SNOL is that it possesses both significant lateral and time-domain resolution differently from state-of-the-art ultrafast [51][52][53][54][55][56][57][58][59] (Table 1, first row) imaging [60][61][62][63][64][65] (second row) techniques for exciton diffusion length measurements, which only possess either of them. As far as ultimate lateral resolution is concerned, PM-SNOL measurements are only limited by the ultimate resolution of the scanning-near field optical microscope used to perform them, which in our case is of the order of the tip aperture, 28,66 and therefore of the order of hundreds of nanometers.…”

Organic Nanostructured Materials for Sustainable Application in Next Generation Solar Cells

“…Nong V. Hoang and colleagues have recently released their work which demonstrates that single-material OPVs are being revived, not only because of their conceptual simplicity and considerably increased stability, but also because they may be used to learn about exciton dissociation and charge separation mechanisms. The production of intermediate inter-molecular charge-transfer (CT) excitons at the homojunction of a single p-and n-type doped organic semiconductor or at the interface of undoped domains with differing molecular orientation and packing has been shown to aid exciton dissociation in such devices [37]. Questions have been raised about whether nanostructured organic photovoltaic devices can exceed the Shockley-Queisser limit.…”