title: Functionally Graded Interfaces: Role and Origin of Internal Electric Field and Modulated Electrical Response.
abstract: We report the tunable electrical response in functionally graded interfaces in lead-free ferroelectric thin films. Multilayer thin film graded heterostructures were synthesized on platinized silicon substrate with oxide layers of varying thickness. Interestingly, the graded heterostructure thin films exhibited shift of the hysteresis loops on electric field and polarization axes depending upon the direction of an applied bias. A diode-like characteristics was observed in current-voltage behavior under forward and reverse bias. This modulated electrical behavior was attributed to the perturbed dynamics of charge carriers under internal bias (self-bias) generated due to the increased skewness of the potential wells. The cyclic sweeping of voltage further demonstrated memristor-like current-voltage behavior in functionally graded heterostructure devices. The presence of an internal bias assisted the generation of photocurrent by facilitating the separation of photogenerated charges. These novel findings provide opportunity to design new circuit components for the next generation of microelectronic device architectures.
authors.affiliation: Bio-inspired Materials and Devices Laboratory (BMDL), Center for Energy Harvesting Materials and Systems (CEHMS), Virginia Tech , Blacksburg, Virginia 24061, United States.
authors.forename: Deepam
authors.initials: D
authors.lastname: Maurya
authors.affiliation: Bio-inspired Materials and Devices Laboratory (BMDL), Center for Energy Harvesting Materials and Systems (CEHMS), Virginia Tech , Blacksburg, Virginia 24061, United States.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Zhou
authors.affiliation: Bio-inspired Materials and Devices Laboratory (BMDL), Center for Energy Harvesting Materials and Systems (CEHMS), Virginia Tech , Blacksburg, Virginia 24061, United States.
authors.forename: Bo
authors.initials: B
authors.lastname: Chen
authors.affiliation: Bio-inspired Materials and Devices Laboratory (BMDL), Center for Energy Harvesting Materials and Systems (CEHMS), Virginia Tech , Blacksburg, Virginia 24061, United States.
authors.forename: Min-Gyu
authors.initials: MG
authors.lastname: Kang
authors.affiliation: Bradley Department of Electrical and Computer Engineering, Virginia Tech , Blacksburg, Virginia 24061, United States.
authors.forename: Peter
authors.initials: P
authors.lastname: Nguyen
authors.affiliation: Bradley Department of Electrical and Computer Engineering, Virginia Tech , Blacksburg, Virginia 24061, United States.
authors.forename: Mantu K
authors.initials: MK
authors.lastname: Hudait
authors.affiliation: Bio-inspired Materials and Devices Laboratory (BMDL), Center for Energy Harvesting Materials and Systems (CEHMS), Virginia Tech , Blacksburg, Virginia 24061, United States.
authors.forename: Shashank
authors.initials: S
authors.lastname: Priya
keywords: electrical transport; ferroelectric; functionally graded interfaces; internal bias; thin film