title: Sb2S3/Spiro-OMeTAD Inorganic-Organic Hybrid p-n Junction Diode for High Performance Self-Powered Photodetector.
abstract: Organic-inorganic hybrid diodes are very promising for solution processing, low cost, high performance optoelectronic devices. Here, we report a high quality p-n heterojunction diode composed of n-type inorganic Sb2S3and p-type organic 2,2',7,7'-tetrakis-(N,N-di-p-methoxyphenylamine)-9,9'-spirobifluorene (spiro-OMeTAD) with a rectification ratio of ∼102at an applied bias of 1 V. On illumination with visible light (470 nm, 1.82 mW/cm2), the current value in our device becomes 8 × 102times that of its dark value even at a zero bias condition. The estimated responsivity value at zero bias is 0.087 A/W which is so far the highest reported for any organic-inorganic hybrid photodiode, to the best of our knowledge. It also exhibits a fast photoresponse time of <25 ms (instrumental limit). More importantly, our device can also detect visible light with power density as low as 8 μW/cm2with a photocurrent density of 1.2 μA/cm2and a photocurrent to dark current ratio of more than 8. We also demonstrate that the values of responsivity, short circuit current, and open circuit voltage of the photodetector can be improved significantly using a thin layer of TiO2hole-blocking layer. These findings suggest Sb2S3/spiro-OMeTAD heterojuncton as a promising candidate for efficient self-powered low visible light photodetector.
authors.affiliation: Department of Solid State Physics, Indian Association for the Cultivation of Science , Jadavpur, Kolkata 700032, India.
authors.forename: Ashok
authors.initials: A
authors.lastname: Bera
authors.affiliation: Department of Solid State Physics, Indian Association for the Cultivation of Science , Jadavpur, Kolkata 700032, India.
authors.forename: Ayon
authors.initials: A
authors.lastname: Das Mahapatra
authors.affiliation: Department of Solid State Physics, Indian Association for the Cultivation of Science , Jadavpur, Kolkata 700032, India.
authors.forename: Sulakshana
authors.initials: S
authors.lastname: Mondal
authors.affiliation: Department of Solid State Physics, Indian Association for the Cultivation of Science , Jadavpur, Kolkata 700032, India.
authors.forename: Durga
authors.identifier: http://orcid.org/0000-0002-0149-1513
authors.initials: D
authors.lastname: Basak
keywords: Sb2S3/spiro-OMeTAD heterojunction; organic/inorganic hybrid diode; photoresponsivity; self-powered photodetector