Fluorine-chlorine co-doped TiO^sub 2^/CSA doped polyaniline based high performance inorganic/organic hybrid heterostructure for UV photodetection applications

• Published in: Sensors and actuators. A. Physical. Vol. 261; p. 94
• Main Authors: Sharma, Shivani, Khosla, Robin, Deva, Dinesh, Shrimali, Hitesh, Sharma, Satinder K
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier BV 01-07-2017
• Subjects: Chlorine; Dark current; Doping; Fluorine; Glass substrates; Heterostructures; Optical properties; Polyanilines; Semiconductors; Spin coating; Thin films; Titanium oxides; Ultraviolet radiation
• ISSN: 0924-4247; 1873-3069

Fluorine-Chlorine, co-doped TiO2 and CSA, doped Polyaniline based n-p heterostructures (F-Cl-TiO2/CSA-PANI) are fabricated on ITO-coated glass substrate by spin coating at room temperature. The Al/CSA-PANI/F-Cl-TiO2/ITO, structures are highly sensitive to UV illumination with a considerable photo-to-dark current contrast ratio of ~381 at -1 V, exceptional ideality factor ~1.9, substantial barrier height ~0.73 eV at zero bias, significantly large responsivity ~24.9 A/W, photoconductive gain ~84.59 and reasonable rise/fall time ~0.6/1.6 s. The CSA-PANI/F-Cl-TiO2 interface/surface morphology, phase analysis, elemental composition and the optical properties of F-Cl-TiO2 are investigated by FESEM, X-ray diffraction, EDX and UV-vis spectroscopy. The significant enhancement in photo current is elucidated with the proposed energy band model and a corresponding collateral conduction mechanism as anticipated for the F and Cl doping in TiO2 based hybrid photodiode. The long-living radiant trapping sites and enhanced photoactivity by F and Cl co-doping divulge a potential candidature of the heterostructure as an alternate for next generation UV photodetection applications.