A planar organic near infrared light detector based on bulk heterojunction of a heteroquaterphenoquinone and poly[2-methoxy-5-(2′-ethyl-hexyloxy)-1, 4-phenylene vinylene]

Abstract

Planar organic detectors for the near infrared region of the light spectrum have been realized, processing from solution the quinoid molecule 5,5′-bis(3,5-di-tert-butyl-4-oxo-2,5-cyclohexadiene-1-ylidene)-5,5′-dihydro-2,2′-bithiophene (QBT), which shows a peculiar absorption at 680 nm. Sensitization of the active material was obtained by creating a bulk donor-acceptor interface with poly[2-methoxy-5-(2′-ethyl-hexyloxy)-1,4-phenylene vinylene], which acts as hole acceptor. Photoexcitation and relaxation dynamics in pristine materials and bulk heterojunction have been investigated by means of pump-probe measurements, revealing charge transfer from QBT to polymer and efficient energy transfer the other way round.

Quinoidal oligothiophenes: new properties behind an unconventional electronic structure

“…As shown in the previous sections, the major strategy to achieve a quinoidal structure in oligothiophenes has been tetracyano-substitution. Other alternative motifs to attain quinoidization of oligothiophenes have been used pursuing the modulation of the electro-optical properties 24,27,28 or an enhanced processability. 74,75 There are two main examples that modify the tetracyano substitution, either partially or totally, to prepare quinoidal thiophenes, such as shown in Fig.…”

“…This was the reason for the preparation of the first example of quinoidal oligothiophene based in the thiophene monomer or tetracyanoquinodimethane thiophene, TCN1QT. 21,22 There are other quinoidal oligothiophenes not based on the tetracyano functionality, for example thiophene derivatives of the Thiele's hydrocarbon 23 or constituted by semiquinones at both free termini of the oligothiophene, [24][25][26][27][28] to cite just a few. In this review we will exclusively focus on the tetracyanoquinodimethane oligothiophene derivatives, and we will refer to them as quinoidal or TCNQ oligothiophenes.…”

Pump‐Probe Spectroscopy in Organic Semiconductors: Monitoring Fundamental Processes of Relevance in Optoelectronics

“…Pump-probe spectroscopy is a powerful time-resolved technique for the characterization of excited-state dynamics in various materials. Owing to its high temporal resolution, pumpprobe has been successfully employed to monitor ultrafast lighttriggered processes like photosynthetic light harvesting, [9][10][11] early photochemical processes involved in human vision, [12][13][14] and charge and energy transfer in organic [15][16][17][18] and organic/ inorganic semiconductors. [ 19 , 20 ] This paper focuses on pumpprobe spectroscopy as a tool to monitor three fundamental processes: optical gain, exciton dissociation and charge transport.…”

Thiol Functionalized Diphenyl Bithiophene for Monomolecular Bistable Layers

“…Indeed, by taking advantage of the versatility of thiophene chemistry, 1 the properties of nonlinear optics, 2 light emission, 3 charge photogeneration, 4 and electrical bistability 5,6 have been addressed by suitable molecular design.…”