title: Dramatic Enhancement in Photoresponse of β-In2S3 through Suppression of Dark Conductivity by Synthetic Control of Defect-Induced Carrier Compensation.
abstract: We report on the synthesis of dense and faceted indium sulfide (β-In2S3) nano-octahedron films on fluorine-doped tin oxide-coated glass by the hydrothermal method and their photoresponse properties in a flip chip device configuration. We have examined the temporal evolution of the phase constitution, morphology, and optoelectronic properties for films obtained after growth interruption at specific intervals. It is noted that, initially, an In(OH)3 film forms, which is gradually transformed to the β-In2S3 phase over time. In the case of the film wherein most, but not all, of In(OH)3 is consumed, an exceptionally large photoresponse (light to dark current ratio) of ∼10(4) and response time(s) (rise/fall) of ∼88/280 ms are realized. This superior performance is attributed to nearly complete carrier compensation achievable in the system under high pressure growth leading to dramatic reduction of dark conductivity. It is argued that the temporally growth-controlled equilibrium between quasi-In interstitials and cation vacancies dictates the optoelectronic properties.
authors.affiliation: †Department of Physics, Savitribai Phule Pune University, Pune 411007, India.
authors.forename: Nilima
authors.initials: N
authors.lastname: Chaudhari
authors.affiliation: ⊥Centre of Excellence in Solar Energy, Physical and Materials Chemistry Division, National Chemical Laboratory (CSIR-NCL), Pune 411008, India.
authors.forename: Lily
authors.initials: L
authors.lastname: Mandal
authors.affiliation: ⊥Centre of Excellence in Solar Energy, Physical and Materials Chemistry Division, National Chemical Laboratory (CSIR-NCL), Pune 411008, India.
authors.forename: Onkar
authors.initials: O
authors.lastname: Game
authors.affiliation: ‡Department of Physics, Nowrosjee Wadia College, Pune 411001, India.
authors.forename: Sambhaji
authors.initials: S
authors.lastname: Warule
authors.affiliation: §UGC-DAE Consortium for Scientific Research, University Campus, Indore 452001, India.
authors.forename: Deodatta
authors.initials: D
authors.lastname: Phase
authors.affiliation: †Department of Physics, Savitribai Phule Pune University, Pune 411007, India.
authors.forename: Sandesh
authors.initials: S
authors.lastname: Jadkar
authors.affiliation: ⊥Centre of Excellence in Solar Energy, Physical and Materials Chemistry Division, National Chemical Laboratory (CSIR-NCL), Pune 411008, India.
authors.forename: Satishchandra
authors.initials: S
authors.lastname: Ogale
keywords: defects; hydrothermal growth; octahedrons; photoluminescence; photoresponse; β-In2S3