Ultrahigh Infrared Photoresponse in Titanium Sesquioxide at Mott‐Insulator Transition
Sukanta Nandi, Rahul Tripathi, Gobinda Das Adhikary, Pramod Kumar, Abha Misra
Abstract
Abstract An ultrahigh infrared (IR) photoresponse is reported in granular titanium sesquioxide (Ti 2 O 3 ), also known as Mott insulator, at its semiconductor−metal transition temperature of 400 K. Ultrahigh photoresponse is obtained due to the IR radiation induced thermal expansion in Ti‐Ti bonding causing a destabilization and depopulation of the band in its metallic state. Moreover, a high voltage responsivity of 1379 V W −1 is achieved, which is significantly higher than any report so far. Both in situ Raman spectroscopy and X‐ray diffraction measurements reveal an important insight beyond the semiconductor−metal transition in Ti 2 O 3 . Moreover, this study opens avenues to evaluate unprecedented properties of Mott insulators in their transition states.