Ferroelectric, dielectric and electrical behavior of two-dimensional lead sulphide nanosheets

Abstract

Two-dimensional pure cubic phase lead sulphide (PbS) nanosheets were synthesized using solid state reaction method at ambient pressure and low temperature ~190 °C. From 210 K–300 K, small polaron hopping conduction mechanism was found to be dominant in PbS nanosheets at frequencies 20 Hz–2 MHz. High values of dielectric constant (~200) and electrical conductivity (of the order of 10−3 S m−1 at 300 K) of PbS nanosheets were extracted suggesting that it is a proficient material for capacitive storage devices. A high value of density of states of the order of 1032 eV−1 cm−3 was obtained for PbS nanosheets. The capacitance-voltage (CV) measurements of PbS nanosheets resulted in a stable butterfly loop due to switching of ferroelectric polarization at 300 K. The permittivity calculated at 0 V capacitance was ~150 and the dielectric loss remained below ~0.50. The polarization-voltage (QV) measurements showed a remnant polarization 23 µC cm−2 in PbS nanosheets. The leakage current density was below 0.5 mA cm−2 in the range ±5 V.

Nanostructured Lead Sulphide Depositions by AACVD Technique Using Bis(Isobutyldithiophosphinato)Lead(II) Complex as Single Source Precursor and Its Impedance Study

“…The fitted results are presented in Table 1. The value of AC conductivity is in the range of 10 −3 S/m which is the same as reported earlier for the PbS nanosheet prepared by solid state method [5]. However, it is greater than PbS nanomaterial synthesized by hydrothermal method, which is in the range of 10 −7 S/m [29].…”

“…Lead sulfide belongs to the chalcogenides semiconductors family, having a direct bulk band gap of 0.41 eV at room temperature [1]. This narrow band gap widens its application in photovoltaic cells [2], infrared detectors [3], thermoelectrics [4], dielectrics [5], gas sensing [6], biosensing [7] and photocatalytic applications [8]. These attributes are all determined by morphology, surface properties, crystal defects, phase and size, which rely completely on their synthetic methods.…”

Development of High-Performance Bismuth Sulfide Nanobelts Humidity Sensor and Effect of Humid Environment on its Transport Properties

“…These values of a , b , c , ρ, and V are in close agreement with those given in the PDF card number 00-006-0333 ( a = 11.15 Å, b = 11.30 Å, c = 3.98 Å, ρ = 6.78 g/cm 3 , and V = 501.59 Å 3 ). To understand the degree of preferred orientation for different crystalline planes, texture coefficient T C ( hkl ) was determined using − where I ( hkl ) is the intensity extracted from XRD pattern of Bi 2 S 3 nanobelts, I r ( hkl ) is the intensity written in the reference PDF card, and n is an integer corresponding to the number of diffraction peaks under consideration. T C ( hkl ) ≤ 1 for randomly distributed planes, and it is >1 for preferentially oriented planes. − The calculated values of T C ( hkl ) for Bi 2 S 3 nanobelts planes are listed in Table .…”

“…In this paper, we used a liquid–solid phase reaction method to produce crystalline Bi 2 S 3 nanobelts at relatively lower temperature (190 °C). This method is easy and generally used to produce several nanomaterials at low cost on a large scale. − …”

Dielectric and impedance spectroscopy of aluminium oxide substituted fused silica samples

“…The relaxation peaks are absent in both sintered and quenched samples in the experimental temperature range. The loss factor value increases as the frequency rise due to charge carriers and unknown defects [10].…”