title: Solution-processed mesoscopic Bi₂S₃:polymer photoactive layers.
abstract: The fabrication of solution-processed nontoxic mesoporous Bi2S3 structures is demonstrated and the suitability of these structures for use in hybrid solar cells investigated. Mesoporous Bi2S3 electrodes are prepared via thermal decomposition of a thin film composed of a bismuth xanthate single source precursor. The resultant Bi2S3 films are made up of regular needles with approximate dimensions of 50×500 nm, as confirmed by scanning electron microscopy (SEM). The crystallinity of the Bi2S3 is found to be dependent on the annealing temperature, as determined by X-ray diffraction. The porous Bi2S3 films are infiltrated with the hole conductor P3HT to generate novel hybrid films, and laser-based transient absorption spectroscopy is used to interrogate the charge-separation reaction at the resulting Bi2S3/P3HT heterojunction. Specifically, optical excitation of the hybrid films results in efficient and long-lived charge separation (microsecond to millisecond timescale), thereby rendering such films suitable for the development of novel low-cost solar-energy conversion devices.
authors.affiliation: Department of Chemistry and Centre for Plastic Electronics, Imperial College London, Imperial College Road, London, SW7 2AZ (UK).
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: MacLachlan
authors.forename: Flannan T F
authors.initials: FT
authors.lastname: O'Mahony
authors.forename: Anna L
authors.initials: AL
authors.lastname: Sudlow
authors.forename: Michael S
authors.initials: MS
authors.lastname: Hill
authors.forename: Kieran C
authors.initials: KC
authors.lastname: Molloy
authors.forename: Jenny
authors.initials: J
authors.lastname: Nelson
authors.forename: Saif A
authors.initials: SA
authors.lastname: Haque
keywords: bismuth sulfide; hybrid photovoltaics; nontoxic materials; solution processing; transient absorption spectroscopy