Abstract
Integration of Spintronics and Optoelectronics, i.e., Optospintronics has the potential to combine the effect of light with the spins of charge carriers. In this attempt, two approaches have been adopted, i.e., Magnetic field tuning of photocurrent and Optical tuning of spin-valve effect. Focussing on the second approach, we have fabricated a coupled organic photodetector and organic spin-valve, i.e., a single Magnetic Organic Photodetector (MOPD) heterostructure, ITO/V[TCNE]x/C60/Co/Au. This MOPD heterostructure exhibits photocurrent generation at room temperature with 40% photocurrent to dark current ratio under illumination of 660 nm red laser light. Also, it shows room temperature negative magnetoresistance as high as -25.85% under dark. Moreover, according to our experimental evidences, this MOPD heterostructure exhibits spin-valve effect with peak up to 3% spin-valve magnetoresistance. Thus, this device can operate as an individual spin-valve, and a photodetector at room temperature. Significantly, coupling between spin-valve and photodetector characteristics is observed for the first time in this MOPD device. Such “cross-talk” between optical response and spin-valve property in a single device are highly significant for future development of novel optically controlled integrated memory logic devices, such as LiFi and Electro-Optical Hybrid Computing technologies. Topological Insulator (TI) based Low Noise, Broadband Infrared photodetector array at room temperature has been developed. Our fabricated heterostructure ITO/TI(Bi2Se3)/Co/Au transit from “admixture of bulk non-conducting and surface conducting state” to “dominating surface conducting state” via bias voltage. A positive photocurrent generation with an optimal photocurrent-to-dark current ratio of 9 × 103 was achieved using broadband infrared light. Our device promises for IR detection and next-generation high-performance focal plane arrays.
Biography
Dr. PUJA DEY is an Associate Professor in the Department of Physics and Joint-Coordinator of Centre for Organic Spintronics and Optoelectronic Devices at Kazi Nazrul University, Asansol, India. Dr. Dey received Ph D degree in Physics from Indian Institute of Technology Kharagpur, India. She has also received CNRS Post-Doctoral Fellowship from CNRS, Strasbourg, France. She has already published more than 70 research papers and three books. Dr. Dey has recently received an International Research Grant from Asian Office of Aerospace Research and Development (AOARD), Air Force Office of Scientific Research (AFOSR), USA. Earlier she received research grants from (i) Department of Science and Technology India; (ii) Board of Research in Nuclear Sciences, Department of Atomic Energy, India and (iii) UGC-DAE CSR, India.
