Swathi Ippili - Academia.edu (original) (raw)

Papers by Swathi Ippili

Polymers, Sep 16, 2023

This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY

Social Science Research Network, 2022

Journal of materials chemistry. A, Materials for energy and sustainability, 2022

Please note that technical editing may introduce minor changes to the text and/or graphics, which... more Please note that technical editing may introduce minor changes to the text and/or graphics, which may alter content. The journal's standard Terms & Conditions and the Ethical guidelines still apply. In no event shall the Royal Society of Chemistry be held responsible for any errors or omissions in this Accepted Manuscript or any consequences arising from the use of any information it contains.

Journal of materials chemistry. A, Materials for energy and sustainability, 2021

An eco-friendly ZnAl–LDH–PVDF composite material is demonstrated for realizing high-performance T... more An eco-friendly ZnAl–LDH–PVDF composite material is demonstrated for realizing high-performance TENG via control of dielectric properties and β-phase of PVDF for simultaneous sensing of pressure and humidity in self-powered way.

ACS Applied Materials & Interfaces, Oct 30, 2020

A single-structured multifunctional device capable of energy harvesting and sensing multiple phys... more A single-structured multifunctional device capable of energy harvesting and sensing multiple physical signals has significant potential for a wide range of applications in the Internet of Things (IoT). In this study, the fabricated single-structured device based on methylammonium lead iodide−polyvinylidene fluoride (MAPbI 3 −PVDF) composite can harvest mechanical energy and simultaneously operate as a self-powered light and pressure sensor because of the combined photoelectric and piezoelectric/ triboelectric properties of the MAPbI 3 −PVDF composite. Light-dependent dielectric and piezoelectric properties of composite films are thoroughly investigated. Light and contact electrification effect on device performance in both piezoelectric and triboelectric modes is also systematically investigated. When the device is operated as a harvester in both piezoelectric and triboelectric modes, remarkable light-driven outputs were observed under illumination; the outputs decreased in the piezoelectric mode, while they increased in the triboelectric mode. Such light-controlled properties enabled the device to operate as a selfpowered photodetector with outstanding responsivity (∼129.2 V/mW), rapid response time (∼50 ms), and satisfactory detectivity (∼1.4 × 10 10 Jones) in the piezoelectric mode. The same device could also operate as a pressure sensor that exhibited excellent pressure sensitivity values of 0.107 and 0.194 V/kPa in the piezoelectric and triboelectric modes, respectively. In addition, the device exhibits a fast response time with long-term on−off switching properties, excellent mechanical durability, and long-term stability.

ACS Applied Materials & Interfaces, Mar 16, 2020

The development of organotin halide perovskites is as an appropriate substitute to replace highly... more The development of organotin halide perovskites is as an appropriate substitute to replace highly toxic lead-based hybrid perovskites, which are a major concern for the environment as well as for human health. However, instability of the lead-free Sn-based perovskites under ambient conditions has hindered their wider utility in device applications. In this study, we report a predominantly stable lead-free methylammonium tin bromide (MASnBr 3) perovskite that has air-stability over 120 days without passivation under ambient conditions. Further, the feasibility of these predominant air-stable MASnBr 3 perovskite for use in the harvesting of mechanical energy is described with the fabrication of an eco-friendly, flexible and cost-effective piezoelectric generator (PEG) using MASnBr 3-polydimethylsiloxane composite films. The fabricated PEG exhibits high performance along with good mechanical durability and long-term stability. This flexible device reveals high piezoelectric output voltage of ~ 18.8 V, current density of ~ 13.76 µA/cm 2 , and power density of ~ 74.52 µW/cm 2 under a periodic applied pressure of 0.5 MPa. Further, the ability of the PEG to scavenge energy from various easily

Crystal Growth & Design, Jan 13, 2017

Organometal halide perovskites become important in the photovoltaic and light emitting devices du... more Organometal halide perovskites become important in the photovoltaic and light emitting devices due to the compositional flexibility with AMX3 formula (A is a monovalent organic ammonium cation; M is a metal ion; X is a halogen atom), imposing a significant demand to develop a synthetic route toward new types of nanocrystals. Although chemical pathways for perovskites nanoparticles were developed on the basis of the reprecipitation method, poor control of the nucleation and growth process results in a large size polydispersity that induces the ambiguities associated with a quantum confinement effect depending on their size. Here, a modified reprecipitation method is presented for the synthesis of CH3NH3PbBr3 perovskite nanoparticles with a controlled nanoparticle size by systematically tuning the feed ratio of the precursors. Fine control of the nanocrystal size provides new insights into the quantum confinement effect observed in microscale and nanoscale perovskite materials, where their energy bandgap is...

IntechOpen eBooks, Dec 14, 2022

Organic/inorganic halide perovskites (OIHPs) have recently emerged as promising candidates for th... more Organic/inorganic halide perovskites (OIHPs) have recently emerged as promising candidates for the creation of high-efficiency electronic and optoelectronic devices, having superior performance because of their unique features such as excellent optical and electronic properties, cost-effective fabrication, solution-processing, and simple device architecture. The noteworthy dielectric and ferro/piezoelectric properties of OIHPs have enabled the design of mechanical energy harvesters (MEHs). Considerable research has been conducted on using OIHPs in the field of piezoelectric and triboelectric nanogenerators. In this chapter, we describe the potential of OIHP materials, such as organic and inorganic halide perovskites, for harvesting ambient mechanical energy and convert it into electrical energy. Furthermore, the crystal structure of OIHPs along with their dielectric, piezoelectric, and ferroelectric properties are discussed in detail. Recent innovations in OIHP-based MEHs are also summarized. The role of OIHP-polymer composites in enhancing the performance and operational stability of nanogenerators is discussed. Certain issues and challenges facing contemporary OIHP-based MEHs are stated, and finally, some directions for future developments are suggested.

Nano Energy, Oct 1, 2018

Organic-inorganic lead halide perovskite (MAPbI 3) has shown remarkable photovoltaic performance ... more Organic-inorganic lead halide perovskite (MAPbI 3) has shown remarkable photovoltaic performance along with unique properties such as ambipolar nature, ferroelectric and ultra-high Seebeck coefficient with low thermal conductivity. The exclusive properties of MAPbI 3 enable to use as a fusion energy conversion material for harvesting of ambient energy such as the thermal, mechanical and solar energy. Many researchers have focused on each of these topics separately. This paper demonstrates a flexible single structured TPS-fusion energy device comprising of interdigitated electrodes (IDEs) and MAPbI 3 to harvest thermal, mechanical and solar energy. A TPS-device is individually operated as a thermoelectric, piezoelectric, and solar (TPS)-energy harvester by independently applying a thermal gradient, mechanical force and solar energy. The TPS-device as a thermoelectric generator is exhibited the higher thermoelectric output performance in in-plane temperature gradient than outof-plane temperature gradient. The obtained piezoelectric output values of the TPS-device as a piezoelectric generator under periodic applied pressure are 1.47 V and 0.56 µA. The TPS-based photovoltaic device is generated an open-circuit voltage of 0.77 V and a short-circuit current density of 0.022 mA/cm 2. This conceptual demonstration of fusion energy harvesting device using IDE-based structure with light active ambipolar material could introduce innovative approaches in fusion-conversion energy technology.

Nano Energy, Mar 1, 2019

An environmentally-friendly lead-free methylammonium tin iodide (MASnI 3) perovskite is successfu... more An environmentally-friendly lead-free methylammonium tin iodide (MASnI 3) perovskite is successfully synthesized using a facile approach of an antisolvent-assisted collision technique under room ambient conditions, which results stability within 24 h under ambient room conditions. The phase transition of MASnI 3 from tetragonal to cubic is first observed at ~ 30 C. Polycrystalline MASnI 3 films reveal a high dielectric constant of ~ 65 at 100 kHz, a low-leakage 2 current density of 7  10-7 A cm-2 at 50 kV cm-1 , well-developed P-E hysteresis loops, and a high piezoelectric coefficient (d 33) of 20.8 pm V-1. The MASnI 3 piezoelectric energy nanogenerator (PENG) shows an output voltage of ~ 3.8 V and an output current density of 0.35 A cm-2. To enhance the piezoelectric output performance, the MASnI 3 films are composited with an environmentally friendly PVDF polymer that had a porous structure. The PVDF-MASnI 3 composite based-PENG reveals a maximum output voltage of ~ 12.0 V and current density of ~ 4.0 A cm-2. A green light-emitting diode (LED) using the PVDF-MASnI 3 PENGs is instantly lighted without need of a storage device, and long-term stability of the composite PENGs is validated for 90 days. This simple and cost-effective solution process is feasible for the fabrication of large-scale, high-performance, and environmental-friendly PENGs based on leadfree organic-inorganic perovskites to extensively implicate in medical and biomechanical applications.

Materials Today Energy, 2018

We report the zinc/aluminum layered double hydroxides (Zn-Al:LDHs) nanosheets that were most faci... more We report the zinc/aluminum layered double hydroxides (Zn-Al:LDHs) nanosheets that were most facilely synthesized at room temperature via an environmentally friendly process and demonstrate their ability to convert mechanical deformation into an electrical stimulus by flexoelectricity. The 1 mm-thick Zn-Al:LDH nanosheets were most facilely synthesized for 2 h at room temperature after dipping the Al (10 at%)-doped ZnO (10AZO) (60 nm)/Au (10 nm)/10AZO (30 nm)-coated PET samples into the carbonated water that the CO 2 in air was naturally captured in the water at room temperature. Based on the nanogenerators fabricated via facilely synthesized nanosheets, we observe a linear relationship between the output voltage and current generated by the centrosymmetric LDHs nanosheets and the curvature from bending, which is a direct evidence for flexoelectricity. We demonstrated the flexoelectric coefficient of our LDH nanosheet-based flexoelectric generators of 1.8 ± 0.35 mCm À1. The output power generated from the LDH nanosheet-based generators via a pushing shows higher performance than that from state-of-the-art flexoelectric PZT-MWCNT-based and piezoelectric BaTiO 3 nanotubes-based generators. These findings could pave the way to the practical exploitation for environmentally friendly synthesis of LDH nanosheets using the CO 2 in air and for harvesting the energy via LDH nanosheetsbased generators.

Transactions on Electrical and Electronic Materials, Oct 27, 2018

We report a high output performance of flexible nanogenerator (NG) based on the composite of PVDF... more We report a high output performance of flexible nanogenerator (NG) based on the composite of PVDF and Zn:Al layered double hydroxide (LDH) nanosheets. The Zn:Al LDH nanosheets were synthesized via the most facile process by dipping the sputtered Al-doped ZnO (AZO)/Ag/AZO multilayer films into deionized water at room temperature. Here, sputtered AZO/Ag/AZO multilayer was served as a bottom electrode of the energy harvesting device as well as for the growth of Zn:Al LDH nanosheets. The PVDF based NG exhibited an output voltage of ~ 1.71 V and a current density of ~ 0.19 μA cm −2 after poling. While poled-PVDF/Zn:Al LDH composite based NGs exhibited an enhancement in the output performance with an output voltage and current density of ~ 6.24 V and ~ 0.655 μA cm −2 , respectively. This simple facile approach can be feasible for the development of large-scale, flexible and an eco-friendly energy harvester that can be widely implemented in self-powered biomedical applications.

ACS Sustainable Chemistry & Engineering, Feb 1, 2022

ACS applied electronic materials, Jul 27, 2020

Compositional tuning of organic-inorganic metal trihalide perovskites (OTPs) via halide (Cl/Br) i... more Compositional tuning of organic-inorganic metal trihalide perovskites (OTPs) via halide (Cl/Br) incorporation has attracted increased attention due to the rapid advancements in the performance of o...